Blocking some commands that could be made by the guests.

Could it be possible to block some commands, like `exit` for example. If a guest wants to quit the room and type `exit` to go out of its terminal, the session of everybody ends, and that's maybe not really cool.

Another idea would be to create blacklists of commands. For example the host could say "I don't want the guests to run xyz commands, without my agreement"

Tell me what you think.