Congressional Research Service 7-5700 www.crs.gov
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 memorandum
1
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).
