I know that we don't have to provide sources of images we share here in fear of plagiarism, but what about those that explicitly claim ownership of painting/photo, like it happened in this case? Shouldn't this be seen as an obvious case of plagiarism since he took someone else's work and claims to be his own?
I have to admit that I don't remember anyone getting a perma-ban or any other punishment for presenting someone else's painting/art as their own - so it's possible that cases like this aren't treated as classic plagiarism. Maybe the administration doesn't want to set a precedent, because it's much easier to prove classic text plagiarism, than this is the case when you had to contact a possible real owner and wait for an answer, and in some cases there may not be an answer.
I hope that some of the staff will clarify this situation, because it is logical that there should be some kind of punishment for such behavior - otherwise we send the message that this is allowed.