Oh yea I've heard plenty of horror stories with clothing shops too; I worked at a chain very similar to CVS, one of the smaller stores in the district but some of the highest foot-traffic. My only solace from and during those times was that many of the people that I worked with and met through there were truly amazing, and I remain great friends with most of them today--it's definitely an environment that can evoke a brothers-in-arms type of feel
So we can call it vandalism then. And I would certainly ask my guests for some reparations if they defecated on my clothes/floor and then walked out like nothing happened, and I certainly would not invite them back!
Nothing like picking up a pile of clothes in a changing room covered in feces to brighten up your day.