Android phones can be infected with an extortionist malware that can lock their devices, and all you have to do is visit an infected website - call G Data.
The extortion program locks the phone on behalf of an authority, often the FBI. He alleges that the owner of the device has committed a criminal activity, such as visiting child pornography websites. Unlocking the phone is then tied to the payment of a more severe “fine” by criminals, but of course it all has nothing to do with the real authorities or the websites the user has previously visited.