TSA has no brains in the organization... The last time I checked a bag, I used nylon ties on the zippers and then put the lock through the ties. My thought was if they needed to get in, then simply cut one tie and that's it. When I got the bag on the other end, not only was the lock gone, but one of the zipper pulls was missing too, the other nylon tie was intact (so the lock had to have been cut).

Now, I don't check bags unless I really have to and NO valuables go in there at all. I still carry the locks to use in the hotel just for stupid security.