This video hack shows exactly why you should never allow your phone to get into the wrong hands.

In the video the user, uses Apple’s digital personal assistant Siri to bypass the PIN number and the in-built fingerprint scanner to make calls from any locked device , including to premium rate phone lines. Mirror has reported that similarly Microsoft’s equivalent to Siri, Cortana, can also be used to bypass security measures and make calls to expensive numbers without being unlocked – and can also send texts. This flaw can cause iPhone owners who lose their smartphone could be at risk of being lumped with giant bills , because whoever finds it could make lengthy calls to long-distance or premium rate numbers. The only way to protect your iPhone from being used to make calls to premium rate phone lines you have to disable Siri on lock screen. Sadly, Apple ships iPhone with default setting on and Siri enabled. Many iPhone users do not turn them off, even if they are never used. You can disable the ability to access to Siri from your lock screen by navigating to Settings then to General then to Passcode Lock. Tap the Siri On/Off slider, under the Allow Access When Locked section, to turn it off. This will stop anyone from accessing Siri while your phone is locked. Resource : Mirror