A bill to require mandatory kill switches on smartphones so that they can be disabled in the event of theft passed the California state senate today and could become law if Governor Jerry Brown signs it in the coming weeks. The bill would mandate (PDF) that all smartphones manufactured after July 1, 2015 to be sold in California come equipped with the means to “render the essential features of the smartphone inoperable when not in the possession of the authorized user.”

The bill was introduced by California Senator Mark Leno (D), and it passed on a vote of 53-20 (PDF). With the approval of Governor Brown, all smartphones sold in California would prompt the user to enable the wiping feature upon initial setup, although opting out would be possible as well. If the smartphone were stolen, the kill switch would have to prevent the phone from being re-activated on a network without the phone's owner's approval. The California bill also stipulates that smartphone designers would have to make it possible for the phone to be re-activated if it found its way back into the rightful owner's hands.

Finally, the bill asks that a civil penalty of between $500 and $2,500 be levied per smartphone if a person is found to be selling stolen phones.

Smartphone theft has long been a problem, with Consumer Reports finding that about 3.1 million devices were stolen in 2013, up from 1.6 million in 2012. The bill had an extensive list of supporters, including the cities of Los Angeles, Oakland, San Diego, and San Francisco, as well as several consumer unions, police groups, and the Utility Reform Network.

The list of opponents included a couple of municipal Chambers of Commerce, the wireless industry lobby CTIA, and the Electronic Frontier Foundation. A spokesperson for the EFF couldn't be reached today, but in a June letter, the group said that it opposed CA SB 962 because options like Find My iPhone, Lookout, Avast Mobile Security, and others already provided a kill switch without a mandate from the state. The EFF also said that such a mandatory feature might be exploited by malicious actors.

Currently Minnesota has passed legislation that requires a kill switch on smartphones, but that feature is opt-in only.