The New York Times reports that the New York City Police Department has been quietly building a collection of phone call records from victims who report that their cellphone has been stolen. The Times says the NYPD routinely subpoenas the call records of theft victims, and that police documents suggest that thousands of subpoenas have been issued every year with each including between dozens and hundreds of phone calls. While it seems reasonable that the police would check phone records to investigate for fraudulent activity, some groups question the practice of holding personal data that's not related to an active criminal investigation.

The Times says that carriers have been cooperative with the NYPD's requests for "large swaths" of call records, and that it appears only Sprint Nextel requires a victim to fill out a consent form that authorizes the company to release call records and location information to the police — the Times says the police don't usually seek consent from victims with major carriers like AT&T, Verizon, and T-Mobile, nor do they issue the subpoenas with the victim's knowledge. Once obtained, the call records are then reportedly added into a database called the Enterprise Case Management System, where each phone number is hyperlinked, allowing detectives to cross-reference phone calls between files. The Times says that the subpoenas cover both the thief's calls, and calls to and from the victim on the day of the theft — including calls placed on the victim's new cellphone if their number is transfered over.

The database doesn't seem particularly useful even in helping solve phone theft crimes

It's not clear what the NYPD plans on doing with the database in the long term, and it doesn't seem like it's particularly useful even in helping solve phone theft crimes. The Times reports that phone records seldom lead to an arrest, and that by the time detectives actually prepare and receive results from a subpoena, most of the unsolved phone cases have been set aside.