At this point, I can’t imagine navigating my way around an unknown city without a GPS or my cell phone. But my call for directions from practically anywhere simultaneously gives away, at least some, of my privacy by leaving a ‘digital trail.’ Local law enforcement agencies are making increasing use of it.
By request, wireless companies can share 'cell tower dumps,' wherein they turn over records of all calls that bounce off a certain tower at a given time. The Washington Post reports that more than 9,000 requests were made for tower dumps last year. One sticking point of this practice is that to find useful information, police departments must collect cell phone data on hundreds, sometimes thousands, of cell phone users who are not under investigation.
The way Christopher Soghoian, principal technologist for the American Civil Liberties Union, sees it, “Tower dumps violate the privacy of hundreds or thousands of innocent people at a time, most of whom will never learn their location information was obtained by the government in order to find the proverbial needle in the haystack.”
While opponents fear a kind of Orwellian imposition, tower
dumps have proven very helpful in tracking down criminals. Christopher Allen,
an FBI spokesman, defends their use saying, “Location information is a vital
component of law enforcement investigations at the federal, state and local
levels.” People think about the FBI doing this, but many don't think of local law enforcement doing the same.
In an article describing how the use of a tower dump led to the arrest of a pair of serial bank robbers known as the ‘High Country Bandits,’ Nate Anderson writes, “Tower dumps aren't like going after targeted cell phone data on a known suspect; they are more like casting a limited dragnet … And tower dumps are usually obtained without a warrant, instead utilizing a ‘court order’ with judicial oversight but a lower burden than ‘probable cause.’”
Two states -- Montana and Maine -- have passed legislation requiring police to obtain warrants for certain cell phone data, and many other states are exploring similar laws.
Police records indicate that data collected from tower dumps can lead to the request for more information including addresses, billing records and logs of calls, texts and locations. As more than 90 percent of American adults now own cell phones, the stakes are high.
Do you think police departments should be required to get a warrant before collecting your cell phone data? Tell us in the comments or in a blog post.