While I have not had the misfortune to lose my phone, I am prepared if it is lost. It is an Android phone, with all important data automatically backed up through Google. It is auto-locked after a a couple of minutes of non use, and it always has a hidden tracking app that works even if the SIM card is changed. From a web site, I can activate the GPS and get the exact position of the phone. I can take photos of the user, and record their conversations and receive a copy to show the police. I can make the phone sound a siren that cannot be switched off by the user, except to remove the battery, and can completely wipe and disable the phone so it is a piece of useless plastic and glass to the thief. Knowing how well it works, if I was ever to turn to thievery, I would never steal a smart phone in case the owner had installed this type of software, as the police would be led directly to me.