Thefts of smartphones have plummeted since manufacturers started implementing kill switches, according to new figures. In London, thefts are down 50%.
"We have made real progress in tackling the smartphone theft epidemic that was affecting many major cities just two years ago," London Mayor Boris Johnson told Reuters.
iPhone thefts were down 40 per cent in San Francisco, and 25 per cent in New York.
Kill switches let smartphone owners turn off their device remotely and render it permanently inoperable, thus removing the incentive to steal handsets.
Johnson, San Francisco district attorney George Gascon and New York state attorney Eric Schneiderman all argued for new laws mandating the kill switches.
"The wireless industry continues to roll out sophisticated new features, but preventing their own customers from being the target of a violent crime is the coolest technology they can bring to market," Gascon said.
Apple, Samsung and Google devices all have kill switches. Microsoft is expected to introduce one with Windows 10 later this year. Some don't protect the user's data unless they opt in, however.
Gascon, Johnson and Schneiderman called on manufacturers to follow Apple's lead, and make the kill switch active by default.