Thief steals phone. Immediately turns it off. Removes sim and places it in another phone. Installs Whatsapp. Whatsapp syncs with the number on the sim. Thief starts receiving Whatsapp messages to that number and is able to respond, and has also messaged contacts from groups (including me) in one-to-one conversations seemingly at will.
Meanwhile my friend has logged onto iCloud in an attempt to find the phone and it's offline the entire time. He uses his girlfriend's phone to interact with the thief in an attempt to recover the phone. Friend has also reported phone to mobile operator, but thief has continued to be able to use Whatsapp for a period of time afterwards.
You'd have thought/hoped.
To clarify, this is what we think happened:
Thief steals phone. Immediately turns it off. Removes sim and places it in another phone. Installs Whatsapp. Whatsapp syncs with the number on the sim. Thief starts receiving Whatsapp messages to that number and is able to respond, and has also messaged contacts from groups (including me) in one-to-one conversations seemingly at will.
Meanwhile my friend has logged onto iCloud in an attempt to find the phone and it's offline the entire time. He uses his girlfriend's phone to interact with the thief in an attempt to recover the phone. Friend has also reported phone to mobile operator, but thief has continued to be able to use Whatsapp for a period of time afterwards.