The introduction of kill switches in mobiles as an anti-theft device has resulted in thefts dropping as it appears to be working.

Internationally the kill switch deterrent appears to be working with London reporting a 50 per cent drop in iPhone thefts, San Francisco a 40 fall and New York a 25 per cent decrease. This follows the creation of the Secure Our Smartphones (SOS) initiative started by the three cities in 2013.

Apple was the first to introduce the Activation Lock system with iOS 7 in September 2013, hence using iPhones as a measure of the effect of the system on thefts. Since then Android has also joined the cause with its own security measures.

So does your phone have protection enabled?

Apple has changed the Activation Lock to make it activated as standard for iPhones with iOS 8. So if you have one of these you'll need to actively turn it off should you not wish to use it. This as-standard activation is the goal of SOS for all phones. To use this on older iPhones go to settings > iCloud > sign in if needed > activate Find My iPhone.

If you're on Android you'll need the latest Android 5.0 Lollipop OS to get its version of the kill switch called Factory Reset Protection, found in settings. Samsung Galaxy S5 users have its Reactivation Lock facility which can be turned on from settings > security should you want it.

Microsoft has yet to add a kill switch on its Windows Phone handsets.

Qualcomm has announced a hardware based kill switch that it will call SafeSwitch. This should offer a more effective level of security, according got Qualcomm. When it will appear and when isn't yet clear.

READ: Android 5.0 Lollipop tips and tricks: Get to grips with a new Android