The really sad part is... even if you DID name and shame him, players can just create new characters.

My best advice if you don't want to change chest permissions for new members would be to completely LOCK 'open recruitment'. I used to have players applying to the FC all the time... low level ones, with nothing more than "I want to join." I was very suspicious because I knew they could steal things and get away with it because I "gave them permission." One time I let an application sit there for a while, and the person who applied eventually withdrew... because they found another FC to join. People were shouting in Ul'Dah about him but there was nothing we could do. Some people followed him around to watch his FC tag change as soon as it did so we could /tell the FC leader... but the best part is, he could have reported US for harassment for following him.

So that is why I suggest just closing FC recruitment altogether. If people really want to join your FC, they can talk to you directly. It's unlikely that someone will want to join out of the blue without any real reason for it. Chances are a thief will not waste the time going through the inevitable 'interview' process. Rather, they will just prey on someone else. It's still possible that people WILL join and try to steal your stuff anyway, that's why I only give new members access to tab three (not very expensive stuff). Once I know I can trust them, I'll give them access to other stuff. It's never foolproof and it's not uncommon to be 'tricked' by someone you thought was a friend, but at least it's not a stranger with free reign of everything. The other reason to lock recruitment is because people might accept the person assuming it's a friend of someone else, when in reality it is just a random person joining.