I know Verizon can tap into our phones for diagnostic reasons and they apparently don't need permission to do so. Plus, I know on Androids at least that they have a Verizon Location Agent which tells them where you are so that they can send offers and advertisements to you for their rewards points program. I wouldn't doubt that they have a way to control your p[hone from afar, or at least find a general area in regards to the origination of the WiFi signal it may be on. You can surely try a Find My iPhone type app or if it's been a week or more....I'm sure the battery is dead and you should really call to deactivate it and have it blacklisted. Otherwise, someone else may find it, use it, and rack up a big bill.