AT&T To Offer Stolen Handset Blocking

The days of rampant cellular handset thefts may be slowly coming to an end, as next week AT&T will offer the ability to completely block handsets from their network after they’re reported stolen by the owner. AT&T is the first wireless carrier to create a GSM-based blocked handset database, which was recommended by the Federal Communications Commission (FCC) earlier this year to help reduce handset thefts. Carriers in other countries have offered handset blocking for several years, and handset theft rates there are much lower than in the United States. The block list uses the unique device ID assigned to each handset, the IMEI, which is independent of the telephone number, account number or other IDs stored on the handset’s SIM card. The ID can only be bypassed or changed using sophisticated techniques that most criminals don’t know about or don’t use. Up to now, AT&T and other carriers have recorded handset IMEIs in their subscriber database, but haven’t used the numbers for anti-theft purposes.

Sprint and Verizon use CDMA technology, which does not use a SIM card to identify the handset or subscriber. As a result, the two carriers already offer individual blocking services. The FCC has required all the carriers to merge their blocked handset databases so stolen handsets cannot be moved from one carrier to another. It’s not clear if the American database will ever be combined with the European and Australia block lists to prevent international movement of stolen handsets.

Criminals typically steal a handset and then remove the SIM card during their getaway, rendering the phone untrackable. Later, the crooks insert their own SIM card into the handset, which is linked to an existing account, and use the phone themselves. They also sell the handsets without a SIM card to others, who then register the phone with another carrier or even AT&T.

Under AT&T’s new service, the owner must contact customer service and specifically request the handset be added to the block list. The customer must perform any remote data wipe before requesting a handset block. Also, once the handset is blocked, it cannot be tracked by any locating service, such as Apple’s  “Find My Phone” service.

Once the block is applied, the person with the handset can never register it on AT&T’s wireless network, even if a different SIM card is inserted or another account is used. However, for now, crooks could still subscribe the handset with another compatible wireless carrier (on T-Mobile, for example). That loophole will be closed later this year when other U.S. wireless carriers begin offering the same service, preventing a blocked handset from being used on any carrier’s network. A technology quirk makes implementing a block list for Verizon and other CDMA carriers more complicated, but the carriers say they will eventually comply with the FCC recommendation.

In the UK, police forces have routine access to the carriers’ blocked handset database, but it’s not know if this feature will be implemented in the U.S.