A large hammer?? Actually, are you referring to the possibility of it being stolen and you want to make sure the thief cannot use it? In the US, they have just started to blacklist phones, you need to report it to the carrier and to law enforcement. Also, change all of the passwords for accounts you have on the phone. If you have activated Find My iPhone before this happened, log into iCloud and see if you can locate the phone. You can also do a remote lock and/or a remote wipe if the phone did not have a passcode on it. Once you wipe the phone, you will no longer be able to track it.