Oh, I'm sure those sophisticated store chains, with extensive inventory tracking, have never thought about things like "inventory shrinkage" or "looting" and they're just putting a bunch of locks around for no particular reason.
Pretty silly of them, right?
My first experience with stores locking up large areas (besides things like electronics/jewelry) was a Target in San Diego. For some reason things like underwear were locked up. A lot of more expensive clothing was not. Have to be honest, if someone is "looting" briefs, I wouldn't get in their way.