How Many Millions of Cellphones Are Police Watching?
In response to a congressional inquiry [1],
mobile phone companies on Monday finally disclosed just how many times they’ve
handed over users’ cellphone data to the FBI and other law enforcement
agencies. By the New York Times’ count [2], cellphone companies responded to
1.3 million demands for subscribers’ information last year from law
enforcement. Many of the records, such as location data, don’t require search
warrants or much court oversight.
Both police and cell service providers had
long resisted releasing details on the scope of cellphone surveillance. But the
new disclosures from cellphone companies still leave a slew of unanswered
questions. Here’s what we have yet to learn.
So more than a million people had their
cellphone records picked up law enforcement surveillance?
Actually, it’s probably far more than that,
but we can’t know for sure.
While the Times calculated the number of
overall requests from law enforcement, each of those requests could cover more
than one person.
For instance, when seeking location
information, law enforcement agencies frequently ask for “tower dumps,” which
list every phone in range of a cell tower at a particular time. In cities,
where cell towers are located close together, it is possible that the locations
of thousands of people might be swept up in a single request.
Even outside of urban areas, ubiquitous
small boxes known as microcells, which help you get cell reception in crowded
places like shopping malls, also record highly precise location data. Sprint
noted in its letter to Congress [3] that each subpoena it received “typically”
asked for information on multiple subscribers.
The Times’ calculation also doesn’t include
specifics from T-Mobile, one of the four largest carriers, because it refused
to provide them [4], saying “T-Mobile does not disclose the number of requests
we receive from law enforcement annually.”
When do police have the right to snoop on your
location data?
The law isn’t settled yet, but location
information is generally far easier for police to get than a warrant for a
wiretap.
A warrant is generally required for police
to place a wiretap or track phones in real time, meaning police must have proof
they have probable cause that the search will reveal evidence of a crime. But
for police to get location data, many courts hold that police need only show
that the data would contain “specific and articulable facts” related to a case.
Privacy activists have long held that
requests for location data require a search warrant to be constitutional. They
say police are essentially using cellphones as tracking devices. But the
Supreme Court hasn’t ruled on the issue, and Congress has yet to pass a law addressing
it.
Police obtain court orders for basic
subscriber information so frequently that some mobile phone companies have
established websites— here’s one [5]— with forms that police can fill out in
minutes.
The Obama Administration’s Department of Justice
has said mobile phone users have “no reasonable expectation of privacy [6].”
For their part, cellphone companies have
supported congressional efforts to make it tougher for police to get location
records. An industry representative spoke at House hearing in favor of a bill
[7] that would require law enforcement agencies to obtain a warrant before
demanding mobile phone users’ location information.
Exactly who are police tracking?
It’s unclear how connected to a criminal
investigation you have to be for law enforcement agencies to request your
cellphone information. Stephen Smith, a magistrate judge in southern Texas who
has advocated for clearer standards for location data requests, said law
enforcement authorities sometimes even request information for every mobile
phone a suspect has called.
“If you call and order a pizza, they might
request the delivery guy’s records,” Smith said. These court orders are usually
kept secret— during an ongoing investigation, police don’t want to tip off a
suspect— but as a result, the vast majority of cellphone subscribers being
tracked have no idea police or the FBI have their historical location
information, whether they were suspected of a crime or not.
What sorts of investigations do the requests
serve?
It’s not clear.
Police departments have frequently argued
that requiring a warrant to obtain cellphone location information would cripple
investigations into violent crimes like kidnapping. But it’s unknown what
proportion of law enforcement requests actually relate to these types of
serious crimes.
“If 80 percent are for drug cases or
robberies and two percent are for child sexual predators, it would help if you
could put a number on those things,” Smith said. “We’d be in a better position
to legislate.”
So what data did police request the most?
That’s also unclear.
Most of the companies didn’t release an
exact breakdown of police requests. So we don’t know how many of the requests
were for location data and how many were for call records, billing information
or other data.
Some of the overall numbers leave questions
too. Sprint has about half the subscriber base of Verizon and AT&T. But it
reported that it received about 500,000 requests overall from law enforcement
last year. That far outpaces its competitors.
We spoke to Sprint spokeswoman Stephanie
Vinge Walsh who said that Sprint counted each person whose data is sucked up
via a police request. It’s not clear exactly how the other companies totaled
the requests they handled.
Which agencies have been requesting the
data?
Once again, we don’t know.
The cellphone companies didn’t say what
proportion of requests was made by federal authorities and what proportion came
from state and local police departments.
The American Civil Liberties Union earlier
this year culled data from dozens of police departments, showing wide
discrepancies [8] in the ease with which police could obtain cellphone location
data. Some police departments routinely obtained warrants; others requested
swathes of records with far less court oversight. In response to a question
from Congress about whether police had misused phone tracking, T-Mobile said it
had identified two cases, which it referred to the FBI.
What does law enforcement do with the data
after it’s collected?
It depends on who is requesting it.
As Smith, the Texas magistrate judge,
pointed out in a recent paper [9], any information that’s not used as evidence
in court is unlikely to become public. Cellphone companies’ data retention
policies [10] vary widely, and the duration of time law enforcement hangs on to
the data it obtains is unknown.