California has become the latest US state to pass a bill mandating that all phones sold in the state must have a “kill switch” to protect data and make stealing the devices pointless.
The bill requires smartphones or other connected devices to have a method for remotely locking and deleting information from 1 July 2015.
The law will apply to all phones sold to consumers online or in physical stores in California, regardless of where the phones are manufactured.
There are some exceptions, mainly for incompatible older handsets, but manufacturers face fines of up to $2,500 per handset if they fail to comply with the law.
In May, Minnesota became the first US state to introduce legislation that requires some form of kill switch on all smartphones sold in the state from July 2015.
But the move by California is more significant because of the state’s high profile in the technology world and population of 38 million, compared with Minnesota’s 5.3 million, according to some US reports.
The legislation by Minnesota and California comes after calls from police departments across the US to clamp down on stolen smartphones, which are involved in one-third of US robberies.
The legislation will also help to improve the data security of mobile devices and prevent thieves from using them to access online accounts.
Read more on kill switches
While Minnesota and California are taking the lead at a state level, the US Congress is reported to be considering similar national legislation.
A year ago, US law enforcement officers, legislators and consumer advocates launched a campaign to push for an international agreement on the need for kill switches.
The Secure Our Smartphones initiative is co-chaired by London mayor Boris Johnson, New York state attorney general Eric Schneiderman and San Francisco district attorney George Gascon.
The initiative is designed to put pressure on the phone industry to help solve the issue of smartphone and tablet theft.
In the US, Apple, Samsung, Verizon, T-Mobile and others have agreed that, from July 2015, all handsets will have anti-theft software installed, although it will not be switched on by default.
In June 2014, Google and Microsoft announced they would add a security kill switch to their Android and Windows Phone operating systems.
But experts have expressed concern that kill signals could be hijacked and used by hackers to disable phones and that phones placed in “airplane mode” will not receive the kill signal.
Other critics of the initiative have said kill switches will not deter criminals from stealing smartphones to strip them for parts.
But authorities claim that Apple's “Activation Lock”, introduced in iOS 7 released in September last year, has helped reduce theft substantially.
According to a report by the New York State Attorney General, in the first five months of 2014, thefts of Apple devices fell by 17% in New York City.
iPhone thefts fell by 24% in London and by 38% in San Francisco in the six months after Apple introduced the feature, compared with the previous six months.