In case if you guys haven't seen this lovely story yet:

http://www.jonengle.com.nyud.net/2009/04/accused

Someone rips the work of a logo designer, posts it on stockart and then stockart sends a bill for 18K to the designer, calls him a fraud and tries to extort the money by calling up his clients and badmouthing him.

Beautiful business model.

PS. Jon is an active and visible member of LogoPond community. There's a lot of people who can vouch for him and his work. It is extremely unlikely that he was ripping other people's work.

PPS. In the light of recent news I edited the subject of the topic.