LAST EDITED ON 11-02-07 AT 12:26 PM (EST)You can't steal it from another. CBS didn't say anything but Terry told us in an interview that, had he wanted to pass the idol to someone, it had to be done on camera. The idol was considered his until HE officially passed it on to someone else. That told us no one could simply grab it from him.
Except for the secrecy, it's the same as the immunity necklace. The immunity winner leaves it around camp and doesn't worry about anyone taking it.