I've also always thought that was a cost/theft issue, but I wonder if its also to prevent people from trying to use the hook-type hangers from hanging things from fire suppression sprinkler heads.
Good point. I recently stayed somewhere with a bolted sign by the sprinkler heads that said not to hang anything on them, lol. Makes me think it happens...a lot.
In general, you are prohibited from traveling with sharp objects in your carry-on bags. Multi-tools (multipurpose tools) with knives of any length are prohibited. Please pack these items in your checked bags. Multi-tools (multipurpose tools) with scissors less than 4 inches may be placed in carry-on bags.
but don't forget (☞゚ヮ゚)☞
The final decision rests with the TSA officer on whether an item is allowed through the checkpoint.