U.S. Officials Push Cellphone Makers To Add Theft Deterrents By Staff Reporter | Jun 13, 2013 02:28 PM EDT (Reuters) - U.S. state and city officials are banding together to pressure cellphone makers to adopt technology, including a "kill switch" to disable stolen phones, that would deter rampant theft of the devices. Authorities have criticized cellphone carriers and handset makers for their perceived unwillingness to make changes to technology to combat the problem. A new coalition slated to be announced on Thursday by New York Attorney General Eric Schneiderman and San Francisco District Attorney George Gascon will analyze patterns behind the thefts and work with Apple Inc and other smartphone makers to create "kill" switches that would render devices inoperable if they are stolen. Cellphone theft has become an escalating and increasingly violent problem, according to law enforcement authorities. About half of San Francisco's robberies last year, for instance, involved stolen mobile devices, according to Gascon. One study found that lost and stolen cellphones cost consumers $30 billion last year. The initiative to combat what has been dubbed "Apple-picking" was expected to be announced before a meeting in New York on Thursday with Schneiderman, Gascon and representatives of Apple, Samsung Electronics Co, and Google Inc's Motorola Mobility and Microsoft Corp. "This nationwide coalition of leaders is committed to doing everything in our power to encourage industry to be good corporate citizens and take responsible steps to ensure the safety of our consumers," Schneiderman said in a statement obtained by Reuters. Aside from New York and San Francisco, the new coalition includes attorneys general from Illinois, Massachusetts, Delaware, Minnesota, Connecticut, Nebraska and Hawaii, and district attorneys, police and other officials from cities including Philadelphia, Boston and Chicago. Amid pressure from authorities, Apple announced on Monday that it would add a new "activation lock" feature in its new mobile software. The new feature, available with the launch of i0S 7 this autumn, will require a legitimate owner's ID and password before an iPhone can be wiped clean or re-activated after being remotely erased. (Reporting By Karen Freifeld; Editing by Barbara Goldberg and Maureen Bavdek)