What's the big deal?

[anjel-kitty.livejournal.com]

So recently a few of my furiends on my FL have been freaking out over the fact some This person on Photobucket has uploaded some of their art to his account. Now mind you he is not claiming it to be his own, or taking credit for it, and even left the signatures in, but a my friends still are really upset he has uploaded their artwork. I really don't see what the big deal is about. As long as this person isn't claiming the art work is his own, I really don't see what the issue is.
But either way I thought I'd ask ya'lls opinion on the matter: Is it considered art thieft to upload someone else's art with out their permission onto your Photobucket account?