lololololol,
Honestly, if you keep it to larger places like Walmart, I don't think it's morally the worst thing ever. Like, anything that involves harassing or assaulting other individuals is significantly worse to me, but this is far from any kind of behavior that's worth encouraging or taking pride in. Also, lol at the fuck capitalism image, hoping that's a joke.
Honestly, I think it's unhealthy to actively engage in risky behavior like that if it can be avoided, and it does seem like most of the people doing it only do so because they get a thrill of the activity, not because of any actual need for the items lifted. Even without any of the moral implications of stealing, it's an activity that focuses on procuring and consuming things just for the sake of having them. It's basically the things I find unhealthy about consumerism combined with an even more impulsive and selfish behavior.
I'm assuming this is a pretty small community of people, though. Also, you know at least some of them aren't serious, so I don't think this is some kind of epidemic.