The addition of "kill switch" anti-theft tools to iPhones and Android handsets appears to be acting as a major deterrent to criminals. London, New York and San Francisco have all announced major drops in the number of reported stolen smartphones since the facilities were added.
A kill switch allows an owner of a stolen phone to send a command that blocks it from being accessed or reset until an ID and passcode are entered. Microsoft has yet to add the feature.
Apple was first to introduce the measure. It included Activation Lock as an option in its iOS 7 operating system in September 2013, and the latest released statistics are based on iPhone thefts over the following 12 months:
London reported a 50% fall in iPhone thefts
San Francisco reported a 40% fall
New York reported a 25% fall