Police officers in Richland County, South Carolina are currently
defending the use of a controversial investigation method that
grants their departments access to thousands of cell phone users’
data in the search for criminals.
The technique, in which law enforcement officials rely on what
are known as “tower dumps,” is an increasingly common policing
tactic in local departments across the country. Following a crime,
law enforcement officials locate nearby cell towers and request all
of the call, text, and data transmissions that occurred during the
crime from the tower’s provider. The majority of the data collected
belongs to individuals with no connection to the crime.
Subjecting yourself to data
seizure through tower dumps is easy. Most cell phone activity
connects you to a tower in a way that police can collect: making
phone calls, texting, and using social media, such as Tweeting or
logging into Facebook.
“So for example if you have a smart phone and you’re checking
your email, that would cause some communication between your cell
phone and one or more cell towers,” Christopher Sogohian, a
principal technologist for the ACLU,
told WLTX. “The police can then go back to the phone
company and ask for identifying information.”
Unlike many forms of data seizure, tower dumps can be executed
a warrant. In accordance with a provision of the Electronic
Communications Privacy Act of 1986, law enforcement can, and often
does, rely on judge-issued
court orders to obtain cell-site data. Such orders don’t need
to meet a probable cause requirement and so are based on
significantly less evidence than is required for a warrant.
According to Brian Owsley, a former judge and current law
professor at Texas Tech University of Law, police can use tower
dumps to collect considerably more personal information than just
phone numbers and locations. In his journal
article on the problems with tower dumps, he says:
Subscriber or customer information also available based on a law
enforcement request may include the person’s name; address;
telephone call records, including times and durations; lengths and
types of services; subscriber number or identity; means and source
of payment, including bank account number or credit card number;
date of birth; social security number; and driver’s license number.
Indeed, any of this information is available simply by presenting
the telecommunications provider with a subpoena.
Additionally, police departments are not required to notify
people when their data has been seized and can
hold on to the information for long periods of time. In South
Carolina, for instance, evidence control laws say that if a suspect
is convicted or pleads guilty, police can keep everything they pull
from a tower dump for up to seven years.
Civil libertarians have been questioning the constitutional
legitimacy of tower dumps since news reports started revealing the
prominence of the practice.
“To turn everybody’s telephone data to the police unrelated to
any suspicion of crime, I think it’s an unreasonable search and
said Jay Bender, a First Amendment attorney who represents
WLTX. “I don’t think that’s permitted by the
After the New York Times published a shocking
breakdown last year on the numbers of cell phone data requests
law enforcement was submitting to cell providers, the ACLU
responded with a condemnation of the practice.
Despite some government officials, like the California District
Attorneys Association, describing tower dumps as “a
search warrant of last resort,” the practice is widespread and
In 2011, AT&T and Verizon received
1.3 million requests for cell phone data (many of which were
tower dumps) and filled more than
500,000 of them. Verizon estimates that over the last 5 years,
law enforcement’s tower dump requests have
increased by 15% annually. T-Mobile reported increases of
from Hit & Run http://reason.com/blog/2013/12/04/police-use-tower-dumps-to-collect-your-c