http://www.nytimes.com/2009/07/06/nyregion/06cellphone.html?_r=2The pivotal role that cellphone records played in these two prominent New York murder trials this year highlights the surge in
law enforcement’s use of increasingly sophisticated cellular tracking
techniques to keep tabs on suspects before they are arrested and build
criminal cases against them by mapping their past movements.
But
cellphone tracking is raising concerns about civil liberties in a
debate that pits public safety against privacy rights. Existing laws do
not provide clear or uniform guidelines: Federal wiretap laws, outpaced
by technological advances, do not explicitly cover the use of cellphone
data to pinpoint a person’s location, and local court rulings vary
widely across the country.
In one case that unsettled cellphone
companies, a sheriff in Alabama told a carrier he needed to track a
cellphone in an emergency involving a child — she turned out to be his
teenage daughter, who was late returning from a date.
For more
than a decade, investigators have been able to match an antenna tower
with a cellphone signal to track a phone’s location to within a radius
of about 200 yards in urban areas and up to 20 miles in rural areas.
Now many more cellphones are equipped with global-positioning
technology that makes it possible to pinpoint a user’s position with
much greater precision, down to a few dozen yards.
To determine
where a suspect’s phone was in the past — as in the Mallayev and
Littlejohn cases — investigators use company records that show a
phone’s approximate location at the beginning and end of a call.
To
track suspects in real time, law enforcement officials must ask a phone
company to “ping,” or send a signal to, a phone; for the effort to
succeed, the phone must be turned on, though it does not have to be in
use. The police can then use a vehicle with signal-tracking equipment
to narrow down the location.
The frequency and ease with which
law enforcement agencies access cellphone data to track people is
difficult to assess. Civil liberties groups recently obtained data from
the Justice Department through a lawsuit showing that in some
jurisdictions, including New Jersey and Florida, courts often allow
federal prosecutors to track the location of cellphone users in real
time without search warrants.
Investigators seeking warrants
must provide a judge with probable cause that a crime has been
committed. But investigators often obtain cell-tracking records under
lower standards of judicial review — through subpoenas, which are
granted routinely, or through an intermediate type of court order based
on an argument that the information requested would be relevant to an
investigation.
In what would be the highest-level court
decision on the issue so far, a federal appeals court in Pennsylvania
is expected to rule this summer on whether search warrants are required
for the most basic cellphone tracking data — the electronic footprints
that cellphone users leave behind in company records, often without
realizing it.
In March, Google
announced that it would require search warrants before releasing GPS
data that pinpoints the movements of customers who use its mapping
applications — like Latitude, which lets people see where their friends
are — on their phones. But phone and Internet companies want Congress to clarify the laws so that they are clear about their legal responsibilities.