Legal Standard for Disclosure of Cell-Site Information (CSI) and Geolocation

Legal Standard for Disclosure of Cell-Site Information (CSI) and Geolocation

MEMORANDUM
June 29, 2010
To:
Senate Intelligence Committee
Attention: John Dickas
From:
Gina Stevens, Legislative Attorney, x7-2581
Alison M. Smith, Legislative Attorney, x7-6054
Jordan Segall, Law Clerk, x7-5123
Subject:
Legal Standard for Disclosure of Cell-Site Information (CSI) and Geolocation
Information

This memorandum1 was prepared to respond to your request for a legal overview of cases concerning
government requests for geolocation information held by private companies to find a customer’s location,
and for a discussion of the scope and conflicting nature of those cases. Geolocation information “can give
the location of a cell phone within several hundred meters.”2 Cell-site information (CSI) generally
“provides the location of the cell phone tower supplying service to a cell phone when it is actually
engaged in a call.”3 You have inquired as to what legal standard is necessary to obtain court ordered
disclosure of cell-site information and geolocation information from cell phone service providers. Most of
the cases discussed below involve government applications to obtain cell-site location information.
As noted by scholars, advances in cellular phone technology “are occurring so rapidly that they blur
distinctions made by legislatures and courts as to what is required to investigate, track, and/or search and
seize a cellular telephone.”4 Reform proponents contend that “ECPA [Electronic Communications Privacy

1 See CRS Report 98-326, Privacy: An Overview of Federal Statutes Governing Wiretapping and Electronic Eavesdropping, by
Gina Stevens and Charles Doyle for further information on this topic.
2 In the Matter of the Application of the United States for an Order Authorizing the Monitoring of Geolocation and Cell Site Data
for a Sprint Spectrum Cell Phone Number ESN, 2006 WL 6217584 (D.D.C. 2006). “ ‘Real time’ cell site information refers to
data used by the government to identify . . . the location of a phone at the present moment . . . ‘prospective’ cell site information .
. . refers to all cell site information that is generated after the government has received court permission to acquire . . . ‘historical’
cell site information . . . constitutes the records stored by a wireless service provider that detail the location of a cell phone in the
past.” Deborah F. Buckman, Allowable Uses of Federal Pen Register and Trap and Trace Device to Trace Cell Phones and
Internet Use, 15 ALR Fed. 2d 537, 545 (2010).
3 Id.
4 Clifford S. Fishman and Ann T. McKenna, Wiretapping and Eavesdropping: Surveillance in the Internet Age § 28.2 (3d ed.
2008).
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Act] is a patchwork of confusing standards that have been interpreted inconsistently by the courts,
creating uncertainty for both service providers and law enforcement agencies.”5
Background
In the area of electronic surveillance law, there are four broad categories of surveillance, each with its
own standard for obtaining court ordered disclosure or monitoring. Those categories are: (1) wiretaps,
which are authorized pursuant to 18 U.S.C. §§ 2510-2522, upon what could be called a “probable cause
plus” showing; (2) tracking devices, which are authorized pursuant to 18 U.S.C. § 3117, upon a Rule 41
probable cause showing;6 (3) stored communications and subscriber records, which are authorized
pursuant to the Stored Communication Act (SCA) upon a showing of specific and articulable facts
showing that there are reasonable grounds to believe that the information sought is relevant and material
to an ongoing criminal investigation;7and (4) pen registers and trap and trace devices authorized pursuant
to the pen register statute (PRS),8 upon the government’s certification that the information sought is
relevant and material to an ongoing criminal investigation.9 Congress amended the SCA by passing the
Communications Assistance for Law Enforcement Act of 1994 (CALEA).10
In criminal prosecutions, the Department of Justice (DOJ) has requested the “disclosure of the location of
cell site/sector (physical address)”11 information at points of call origination, termination, and during the

5 Digital Due Process Coalition, Modernizing Surveillance Laws for the Internet Age, available at
http://www.digitaldueprocess.org/index.cfm?objectid=DF652CE0-2552-11DF-B455000C296BA163.
6 Rule 41 provides that the government may secure a warrant upon a showing of probable cause. A judge must issue the warrant
after receiving an affidavit from a law enforcement officer if there is probable cause to search for and seize a person or property
or to install and use a tracking device. Fed. R. Crim. P. 41. A tracking device is defined in 18 U.S.C. § 31117 (2006) as “an
electronic or mechanical device which permits the tracking of the movement of a person or object.”
7 The Stored Communications Act (SCA), codified at 18 U.S.C. §§2701-2712 (2006), prohibits a provider of an electronic
communication service or remote computing service from disclosing the contents of, or a record or other information pertinent to,
a customer or subscriber to the government, except as otherwise authorized. Electronic communications excludes any
communication from a tracking device, as defined in 18 U.S.C. § 3117 (2006), “an electronic or mechanical device which permits
the tracking of the movement of a person or object.” The exceptions to the governmental prohibition are when the government
has: (1) obtained a warrant under the Federal Rules of Criminal Procedure, (2) obtained a court order under § 2703(d), (3)
obtained subscriber consent to disclosure, (4) submitted a written request relevant to an investigation of telemarketing fraud, or
(5) sought basic account information.
8 The pen register statute, codified at 18 U.S.C.S. § 3121 et seq. (2006), requires that, absent emergency, the government must
obtain a court order prior to installing or using a Trap and Trace, it may do so merely upon certification that the information
likely to be obtained is relevant to an ongoing criminal investigation being conducted by that agency. 18 U.S.C.S. § 3122(b)(2)
(2006). Such orders routinely authorize real-time electronic monitoring of telephone call information for a limited duration,
typically sixty (60) days. 18 U.S.C.S. § 3123(c) (2006).
9 See In re Application of the United States of America for Pen Register and Trap/Trace Device with Cell Site Location
Authority, 396 F.Supp.2d 747, 753 (S.D.Tex.2005) (hereinafter “Smith Opinion”).
10 CALEA requires telecommunications carriers to acquire and implement technology to isolate and provide, on appropriate
lawful authority, intercepted content and call-identifying information. Telecommunications carriers must provide access to call-
identifying information before, during, or immediately after the transmission of a wire or electronic communication. Information
acquired solely pursuant to the authority for pen registers and trap and trace devices may not yield information that discloses the
physical location of the subscriber, except to the extent that the location may be determined from the telephone number. See 47
U.S.C. §§ 1001 et seq. (2006).
11 In the Matter of an Application of the United States for an Order (1) Authorizing the Use of a Pen Register and a Trap and
Trace Device and (2) Authorizing Release of Subscriber Information and/or Cell Site Information, 384 F. Supp. 2d 562, 563
(E.D.N.Y. 2005) (hereinafter “Orenstein Opinion I”).

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progress of the call. This information is stored by cellular telephone companies when the cellular
telephone is operational through the phone’s roaming antenna function, which allows the phone to link
with the closest cell phone tower for the service provider. The information catalogs these changes in
tower connection and also is cataloged in the context of individual telephone calls, showing the closest
tower at the beginning of the telephone call and the closest tower at the end of the call. This information
is limited, however, because towers can be up to 10 or more miles apart, and the location is not pinpointed
since there is no GPS information involved. Records also do not indicate a phone’s distance from the
serving tower. The information can, however, provide a general indication of where a cell phone call was
made, and the location can be pin-pointed more specifically through a process known as triangulation in
which the angles of the various signals are calculated when two cell towers are involved.12 In 2005, the
FCC mandated that cell phones be capable of being located within 100 meters for public safety
purposes.13
Legal Overview of Cases
Federal district courts are divided on the proper statutory authority and procedural requirements for
government access to CSI and geolocation information.14 Several magistrates have thoroughly examined
the government applications for CSI.15 For example, a court in the Western District of Pennsylvania
rejected the government’s application, and affirmed the magistrate’s order requiring a warrant based on
probable cause under the Fourth Amendment.16 The Third Circuit Court of Appeals heard oral arguments
in February and is preparing to rule on an appeal denying the government’s application for cell-site
location information, based on the SCA alone or in tandem with the pen register statute.

12 See “Smith Opinion I,” 396 F. Supp. 2d 747.
13 In the Wireless Communication and Public Safety Act, P.L. 106-81, a nationwide emergency service for cell phone users was
mandated with Congress recognizing the privacy interest of one’s physical location. As such, in authorizing disclosure of
specifically limited location information for emergency services they disallowed access to location information unless expressly
authorized. 47 U.S.C. § 222(f). Location information provided to 911 operators is comprised of GPS data, triangulation data,
and single cell site data. See generally Laurie Thomas Lee, Can Police Track Your Wireless Calls? Call Location Information
and Privacy Law, 21 CARDOZO ARTS & ENT. L. J. 381, 384-88 (2003).
14 Compare In re Application of the United States for an Order Authorizing the Disclosure of Prospective Cell Site Info., 412
F.Supp.2d 947 (E.D. Wis. 2006) to In re Application of U.S. for an Order for Disclosure of Telecommunications Records and
Authorizing the Use of a Pen Register and Trap and Trace, 405 F. Supp. 2d 435 (S.D.N.Y. 2005) (hereinafter “Gorenstein
Opinion”).
15 It is to be noted that there have been numerous decisions discussing the issue of cell-site information, particularly at the
Magistrate level where the issue has been painstakingly analyzed. Attempting to represent all cases could constitute a treatise. See
Ian James Samuel, Warrantless Location Tracking, 83 N.Y.U. L. REV. 1324, n.9 (2008).
16 In the Matter of the Application of the United States of America for an Order Directing A Provider of Electronic
Communication Service to Disclose Records to the Government, 534 F. Supp. 2d 585 (W.D. Pa. 2008). The principal object of
the Fourth Amendment is the protection of privacy and people rather than property and places. In Katz v. United States, 389 U.S.
347-353 (1967), the Court stated that “[T]he test propounded . . . is whether there is an expectation of privacy upon which one
may “justifiably” rely.” That is, the capacity to claim the protection of the Amendment depends not upon a property right in the
invaded place but upon whether the area was one in which there was reasonable expectation of freedom from governmental
intrusion. This reasonable expectation must have a source outside of the Fourth Amendment, either by reference to concepts of
real or personal property law, or to understandings that are recognized and permitted by society. Rakas v. Illinois, 439 U.S. 128
(1978). When the Fourth Amendment protects information it does so with a probable cause standard and particularity backed by
the exclusionary rule.

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It does not appear that another court has ruled in such a manner, requiring a warrant under the Fourth
Amendment based upon a showing of probable cause for government access to cellular-telephone-derived
location information, historic or prospective. Many courts have rejected Fourth Amendment challenges
based on the fact that (1) the information tells nothing about the subject’s location in the present when it is
historical cell-site information, (2) the information does not reveal a particular location unless involving
multiple towers leading to triangulation data, and (3) the issue can be raised later in the context of a
motion to suppress.17 In other words, the information obtained is insufficient to presently pinpoint a
particular individual and his or her location.
Courts rejecting government applications have focused on the absence of explicit standards in the relevant
statutes, 18 the Pen Register Statute (PRS)19 and the Stored Communications Act (SCA).20 These courts
have also expressed concern that the government might use the information to make the cell phone a
“tracking device.” These courts cite congressional testimony from the former director of the Federal
Bureau of Investigation about certain aspects of the PATRIOT Act that purportedly limited the use of the
statutes at issue for cell-phone monitoring applications. These cases find that the applicable standard is
probable cause under Rule 41 of Federal Rules of Criminal Procedure and that the government has not
made this showing, thus refusing to issue the authorization.
Other cases granted the government’s application.21 Judges accepting these applications have focused on
the explicit text of CALEA, which states that cell-site information may not be obtained “solely pursuant”
to the Pen Register Statute.22 These courts permit the government to obtain cell-site information after
meeting the requirements of both the PRS and § 2703 of the SCA. These courts point out that Section
2703 of the SCA fulfills the purpose of Section 1002 exception, to require more than the minimal
authorization imposed under the PRS, but does not require a probable-cause showing. In many of these
cases, moreover, the judges ensured that the orders authorized only limited information, minimizing the
concern that a cell phone could be used as a kind of “tracking device.”
A brief survey of cases and issues will be discussed below.

17 See, e.g., In Re Application of the United States of America for Orders Pursuant to Title 18, United States Code, Section
2703(d), 509 F. Supp. 2d 76, 80-81 (D. Mass. 2007) (hereinafter “Massachusetts Opinion”).
18 See, e.g., In the Matter of the Application of the United States of America for an Order Authorizing the Release of Prospective
Cell Site Info., 407 F.Supp.2d 132 (D.D.C. 2005); In the Matter of the Application of the United States of America for an Order
(1) Authorizing the Installation and Use of a Pen Register and Trap and Trace Device and (2) Authorizing Release of Subscriber
Info. and/or Cell Site Info., 396 F.Supp.2d 294 (E.D.N.Y. 2005) (hereinafter “Orenstein Opinion II”).
19 18 U.S.C. §§ 3121-27
20 18 U.S.C. § 2703.
21 See, In the Matter of the Application of the United States for an Order: (1) Authorizing the Installation and Use of a Pen
Register and Trap and Trace Device; and (2) Authorizing Release of Subscriber Info. and/or Cell-Site Info., 411 F.Supp.2d 678
(W.D.La.2006); In the Matter of the Application of the United States of American for an Order Authorizing the Installation and
Use of a Pen Register and Caller Identification System on Tel. Nos. [Sealed] and [Sealed] and the Prod. of Real Time Cell Site
Info., 402 F.Supp.2d 597 (D.Md.2005).
22 47 U.S.C. § 1002(a)(2). See, In the Matter of the Application of the United States of America for an Order Authorizing the
Installation and Use of a Pen Register Device, a Trap and Trace Device, and for Geographic Location Information, 497 F. Supp.
2d 301, 307 (D. Puerto Rico 2007) (hereinafter “Puerto Rico decision”).

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Cell-Site Information is Protected by the Fourth Amendment and the
Government Must Obtain a Warrant Based Upon Probable Cause
Currently, the Third Circuit Court of Appeals is considering a district court’s denial of the government’s
request to obtain cell-site location information concerning a subscriber that was living in another state and
linked to large-scale narcotics trafficking, evading visual surveillance. The district court rejected the
government’s application, and affirmed the magistrate’s order requiring a warrant based on probable
cause.23 In an extensive opinion, the Magistrate denied an ex parte application by the government
pursuant to the SCA. The court addressed whether the government could obtain an order for certain cell
phone information that disclosed the user’s location without showing probable cause. The government
contended that it could obtain such an order based on a reasonable belief that such information was
relevant to a criminal investigation under the SCA. The court concluded that the SCA, whether alone or in
tandem with other statutes, did not authorize access to an individual’s cell-phone-derived location
information, either past or prospective, on a simple reasonable relevance standard. The court held that the
SCA expressly set movement/location information outside its scope by defining “electronic
communications” to exclude any communication from a tracking device. It also found that other statutes
cited by the government did not drop the Fourth Amendment requirements and that legislative history
made clear that Congress was not seeking to amend the background standards, such as probable cause,
governing disclosure of tracking information. The court thus denied the government’s requests for
cellular-telephone-derived location information, historic or prospective, absent a showing of Fourth
Amendment probable cause.
On appeal, the government maintains that since § 2703(d) allows for the compelling of a record
pertaining to a subscriber, by a provider of an electronic communication service, historical cell-site usage
information falls within the statute’s ambit. The government also contends that this information falls
clearly within the Stored Communications Act’s (SCA) plain language. Under the government’s reasoning
a cell phone company is a provider of electronic communication service, because it provides users the
ability to send or receive wire or electronic communications, and cell-site information is a record
pertaining to a subscriber without providing the content of the information of the call.24
The government also maintains that the district court conflated the historical and prospective use of cell
phones. As such, they maintain that CALEA (47 U.S.C. § 1002) does not apply because the information is
not being acquired solely pursuant to the authority for pen registers and trap and trace devices. The
government relies on the separate authority in the SCA, and CALEA did not intend to incorporate the
provisions of the SCA in its provisions.25 CALEA, as well as the Wiretap Act and pen register statute,

23 In the Matter of the Application of the United States of America for an Order Directing A Provider of Electronic
Communication Service to Disclose Records to the Government, 534 F. Supp. 2d 585 (W.D. Pa. 2008). The principal object of
the Fourth Amendment is the protection of privacy and people rather than property and places. In Katz v. United States, 389 U.S.
347-353 (1967), the Court stated that “[T]he test propounded . . . is whether there is an expectation of privacy upon which one
may “justifiably” rely.” That is, the capacity to claim the protection of the Amendment depends not upon a property right in the
invaded place but upon whether the area was one in which there was reasonable expectation of freedom from governmental
intrusion. This reasonable expectation must have a source outside of the Fourth Amendment, either by reference to concepts of
real or personal property law, or to understandings that are recognized and permitted by society. Rakas v. Illinois, 439 U.S. 128
(1978). When the Fourth Amendment protects information it protects that information with a probable cause standard and
particularity backed by the exclusionary rule.
24 See Brief of Government, p. 11 (citing “Gorenstein Opinion”, 405 F.Supp. 2d 435, 444).
25 The Government cites the expressio unius est exclusio alterius canon for its proposition. The expression of one is the exclusion
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regulates exclusively prospective, ongoing surveillance. The SCA conversely handles historical
communications and thus its different mechanism for obtaining records, a subpoena, is applicable.
Appellee’s arguments that a magistrate can demand probable cause under the SCA, according to the
government, violates the plain language of the statute.26
Historical cell-site information, the government argues, is also not a communication from a tracking
device because it is not an electronic communication, it is information from a cell-phone which is a wire
communication since it involves the human voice. According to the Government, communication cannot
be both electronic and wire in nature.27 Attempting to distinguish a cell-phone from a tracking device, the
government argues that a homing device is installed by the government, and the ECPA embraces only the
narrow terms of when the government applies to have a tracking device installed. The government
maintains that electronic tracking devices are defined separately from cellular telephones in the ECPA and
cellular telephones are protected as communications under the Wiretap Act and Stored SCA.28 A contrary
result, according to the government, mitigates the privacy protections given to cellular telephones under
the Wiretap Act, such as in text messages or email.
Regarding the Fourth Amendment, the government maintains there is no reasonable expectation of
privacy and cites U.S. v. Miller, 425 U.S. 436 (1976) and Smith v. Maryland, 442 U.S. 735 (1979). It
maintains that the information is far too imprecise and in the possession of a third party, the telephone
company. Thus it is not the individual’s private information but information handled by the company
internally and not typically known by the customer. Even if found to have a greater link to the customer,
the government states that the information is like that of a dialed telephone number, essential information
for the telephone call to be completed and voluntarily turned over. The government also distinguishes the
GPS beeper cases because the monitoring is analogous to the monitoring of beeper signals that do not
reveal facts about the interior of a constitutionally protected space. The user’s exact location is not
discerned.29
Appellee maintains that a warrant founded upon Fourth Amendment probable cause, or an exception to
the warrant requirement, is necessary. Responding to the government, appellee maintains that, (1) the
information is far more precise than the government asserts and can be used to reconstruct a user’s exact
location through triangulation and GPS technology; (2) the public has manifested a subjective expectation
of privacy in cell-phone records through polling showing a desire for a warrant requirement and it is
objectively reasonable due to the pervasive role cell-phones play in daily lives as well as the hidden,
continuous, indiscriminate, and intrusive monitoring which takes places requiring extensive judicial
oversight;30 (3) the case law cited by the government does not create a third party exception because the

(...continued)

of the other, which it maintains does not reach an absurd result due to the necessity of the different evidentiary thresholds
(certification of relevance for pen register v. specific and articulable facts for the SCA).
26 See Government’s Reply Brief at 11-15 (discussing the limiting term “only” in the statute).
27 18 U.S.C. §§ 2510(1), (12)(A) (2006).
28 See Government’s Brief, 18-20, 22 (citing 18 U.S.C. § 3117, “Massachusetts Opinion,” 509 F. Supp. 2d 76; “Gorenstein
Opinion,” 304 F. Supp. 2d 435 (S.D.N.Y. 2005); and the legislative history of the EPCA).
29 United States v. Knots, 460 U.S. 276 (1983); United States v. Karo, 468 U.S. 705 (1984).
30 Brief of Appellee at 7-9 (describing how the process of retrieving the cell-history information meets the factors elucidated and
citing Berger v. New York, 388 U.S. 41 (1967) as well as United States v. Tores, 751 F.2d 875 (7th Cir. 1984)).

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case law involved third parties that had greater control over the information, making their situation more
akin to a second party transaction;31 and (4) the information is not kept in the normal course of business.
Cell-Site Information is Subject to Rule 41 Because a Phone is a Tracking
Device Requiring Probable Cause
There have been two highly cited opinions out of the Eastern District of New York. In the first opinion,
the court held that cell-site information, even when referencing a single cell tower, does not fall within the
SCA, and “is not information that the government may lawfully obtain, absent a showing of probable
cause.”32 The standard under the SCA for such an order is “specific and articulable facts showing that
there are reasonable grounds to believe that [such information is] relevant and material to an ongoing
criminal investigation.”33 The magistrate concluded that cell-site information was not an electronic
communication because tracking devices are excluded from the definition of an electronic communication
under the SCA.34 While the phone itself is not a tracking device, the authorization “would effectively
allow the installation of a tracking device without the showing of probable cause normally required for a
warrant.”35 While the government’s application for a pen register in the context of cell-site history
information falls within the pen register statute’s express terms as “routing, addressing, and signaling
information,”36 the CALEA prohibits the disclosure by a telecommunications carrier of “any information
that may disclose the physical location of the subscriber”37solely on the basis of a pen-register or trap and
trace, on anything less than probable cause.38 This reflects the Congress’ concerns about infringing
individual Americans’ privacy rights.39
In a second opinion, the magistrate again rejected the government’s application, upon request of
reconsideration, again citing the CALEA and its legislative history as prohibiting access to the cell-site
information based solely on the authority of a pen-register or its combination with the SCA.40 The
magistrate heavily relied on a decision from the U.S. District Court for the Southern District of Texas, in
expanding upon its rejection of the government’s application.41 He found that not only was the
information from a tracking device, excluding it as an electronic communication under the SCA, but also
that the record does not “involve the transfer of the human voice.”42 Thus it also could not be a wire

31 See Appellee’s Brief at 16.
32“Orenstein Opinion I,” 384 F. Supp. 2d 562, 564.
33 “Orenstein Opinion I,” 384 F. Supp. 2d at 563 (citing 18 U.S.C. § 2703(d) (2006)).
34 See Id. at 564. See also 18 U.S.C. §§§ 2711(1), 2510(12), 3117 (2006). A tracking device is defined broadly as “an electronic
mechanical device which permits the tracking of movement of a person or object.” 18 U.S.C. § 3117(b) (2006).
35 Id.
36 18 U.S.C. § 3127(3), (4) (2006).
37 47 U.S.C. § 1002(a)(2)(B) (2006).
38 “Orenstein Opinion I,” 384 F. Supp. 2d at 565. This would take the form a Rule 41 probable cause order. See “Smith Opinion
I,” 396 F. Supp. 2d at 751-53.
39 Id. (citing the House Judiciary Committee Report on CALEA and the testimony of former FBI Director Louis Freeh stating
“the authority for pen registers and trap and trace devices cannot be used to obtain tracking or location information other than that
which can be determined from the phone number”).
40 “Orenstein Opinion II,” 396 F. Supp. 2d 295, 306-07.
41 “Smith Opinion I,” 396 F. Supp. 2d 747.
42 “Orenstein Opinion II,” 396 F. Supp. 295, 308.

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communication.43 The court also maintained that the SCA could not pull the government out of the
“solely pursuant” language of the CALEA because of the profound structural differences between the
SCA and electronic surveillance statutes. The magistrate wrote, “Congress did not intend the former to be
a vehicle for allowing prospective, real-time surveillance of a mobile telephone user’s physical location
and movement during the course of a call.”44 He also concluded that the SCA did not apply to relieve the
prohibitions of CALEA because the SCA did not change “existing surveillance capabilities.”45 Regarding
the pen-register statute, the magistrate maintained that the “signaling information” provisions of the pen-
register statute were merely to reach electronic communications, such as email, not cell-site information.46
As such, according to the magistrate a showing of probable cause was necessary by the government.47
The SCA’s applicability to purely historical cell-site information, however, seemed to be left open by the
magistrate to the SCA’s lower threshold.48 Yet the decision noted even if granted, this only authorizes a
provider to disclose the information, not the interception of such information by law enforcement.49
Similar to the cases from the Eastern District of New York, a U.S. district court from the Southern District
of Texas has rejected the Government’s hybrid order theory. The court maintained that the PRS is not the
exclusive mechanism by which the government can retrieve cell-site information based upon the “greater
includes the lesser maxim.” In other words, when a showing of greater authority is asserted, such as a
super-warrant under the Wiretap Act allowing for the recording of conversations, the Government is also
given the lesser authority to monitor tracking devices. As such, Rule 41 could allow for the Government
to access the cell-site information it desires and “is sufficiently flexible to include within its scope
electronic intrusions authorized upon a finding of probable cause.”50 Removing this exclusivity of the
pen-trap statute, according to the magistrate, collapses the necessity of moving to CALEA and the SCA.
However even if viewed as non-persuasive, the emphasis on the word “solely” in the CALEA seems to be
misplaced because it is not mentioned in the legislative history and a pen register may not be the sole
mechanism for obtaining cell-site information.51 Moreover, the word “solely” could be interpreted to

43 See 18 U.S.C. §§ 2510(1), 18 (2006) (stating that a wire communication “must involve a transfer of the human voice”).
44 “Orenstein Opinion II,” at 309. In coming to this conclusion Judge Orenstein rejected the Government’s instantaneous storage
theory that cell-site information becomes historical once captured relying on the statute’s present tense phrasing to suggest that
the items must already be in existence. See 18 U.S.C. 2703(d) (2006) (“are relevant and material to an ongoing investigation”).
45 Id. at 319-20 (citing testimony former FBI Direct Louis Freeh at the Senate Judiciary Committee “All transactional information
is . . . exclusively dealt with in the SCA and . . . Congress treats law enforcement’s use of pen registers and dialing information
differently than transactional information.”)
46 Id. at 318 (citing the legislative history of the USA PATRIOT Act amendments).
47 Judge Orenstein left open the possibility of a super-warrant for prospective monitoring of cell-site information in future
litigation but did not decide the issue. See id. at 322, 324-25.
48 Id. at 312-13 (“I have no quarrel, that a court may properly, under § 2703, compel a provider to disclose historical cell site
information about past calls that it currently has in electronic storage”). The U.S. District court in Massachusetts when analyzing
an application for purely historical cell-site information did in fact approve its use under the SCA because the record holder cell-
phone company is a provider of an electronic communication service, the cell-site data is a record pertaining to a subscriber in
that it is stored or archived by the cellular company, and the information is not content information disclosing any substance of
the call itself. See “Massachusetts Opinion.” See “Puerto Rico Decision” for contra result when assessing cell-site information in
the context of the SCA and whether it constitutes a “record.”
49 Id. at 314-15.
50 In the matter of the Application of the United States of America for an Order Authorizing (1) Installation and Use of a Pen
Register and Trap and Trace Device or Process, (2) Access to Customer Records, and (3) Cell Phone Tracking, 441 F. Supp. 2d
816, 830 (S.D.T.X. 2006) (hereinafter “Smith Opinion II”) (citing United States v. New York Tel. Co., 434 U.S. 159 (1977)).
51 Id. at 832-33 (discussing an analogy that a law degree may not be sufficient to practice law as an additional passage of the bar
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embrace the hierarchy of electronic surveillance law, in that greater showings are necessary due to the
information requested. While “some amount of legal process will be necessary to obtain location
information, certification of relevance . . . is not enough.”52 Without the word “solely” according to the
court, CALEA could be erroneously interpreted that no amount of process would access the cell-site
information.53 Finally, in regards to the SCA, the court cites the SCA’s clear statutory prohibition of a
phone company “disclosing subscriber information to any governmental entity except under certain
carefully delineated circumstances.”54 Six exceptions are listed and none include or implicate the pen-
register statute.
Cell-Site Information Requires a Pen Register and § 2703 of the Stored
Communications Act Despite the Prohibitions of CALEA
A minority of courts have held that the government need not establish probable cause under Rule 41 to
access cell-site information. The most cited of these opinions is from the Southern District of New York.55
In allowing for the cell-site information based upon the “reasonable and articulable facts,” provision of
the SCA, the court highlighted that the information would not be gleaned while the telephone was not on
a phone call and was only from one cell tower, mitigating the possibility of triangulation data. In
reference to the CALEA terms that prohibits monitoring “solely pursuant” to a pen register, the court
maintained that this meant that a pen register could be combined with some other form of statutory
authority, which the SCA satisfied because it is more than the minimal authorization of a pen-register
order. The court was careful to limit its holding to information coming from a single tower, from the
user’s particular telephone, and transmitted by the provider to the government.56
Conclusion
A majority of jurisdictions have found the probable cause standard of Rule 41 applicable for government
access to cell-site information. These courts appear to differentiate between historical information and
prospective monitoring. However, other jurisdictions have held that a mere showing of reasonable and
articulable facts is sufficient. Further litigation, particularly in the Court of Appeals, may clarify the issue.

(...continued)

is required, but also that a law degree may not be necessary to practice law as some states allow individuals to sit for the bar after
informal study).
52 Id. at 833.
53 Id.
54 Id. at 834 (citing 18 U.S.C. § 2703(a)(3) (2006).
55 “Gorenstein Opinion,” 405 F. Supp. 2d 435.
56 This ruling was expanded to encompass prospective cell-history information and the tracking device exception to the SCA was
rejected because cell phones are not installed but carried and used voluntarily. See In the Matter of Application of U.S. for an
Order for Disclosure of Telecommunications Record and Authorizing the Use of a Pen Register and Trap and Trace, 411 F. Supp.
2d 678 (W.D. La. 2006).