How often do police use cell phone data?

The ACLU recently released the results of an extensive study that surveyed more than 200 local police agencies to see details about their data-gathering habits from cell phone providers. 

In a response to that study, California State Senator Mark Leno (D), introduced legislation that would require mobile companies to not only publicly disclose the number of law enforcement location-related requests that they receive, they would also be prohibited from disclosing such information without a warrant.

CTIA (the wireless industry trade group) sent a letter to Leno in response, explaining that they oppose the legislation due to the “unduly burdensome and costly mandates on providers and their employees” that it would create.

Of course, the ACLU fired back a letter in response that letter, arguing that wireless companies should have their customers’ privacy at heart, and Nicole Ozer, an ACLU policy director in California took issue with the idea that a reporting requirement would be burdensome as the firms must already keep track of that data. 

What kind of data are they talking about?  Mostly location information and “pen trap and trace” data that shows whom a caller is talking with  Federal agencies are supposed to report annually how often they use these investigative techniques, but the Justice Department repeatedly fails to provide such reports to Congress.

Other companies already disclose how often they are requested to provide information by law enforcement, Google voluntarily provides that data on their Transparency Report website.  But without data from cell phone providers it is difficult to tell whether or not customers privacy rights are truly being abused.