I hired a designer to do a "mockup" design for a cam/social networking site. He ended up pretty much copying the F4F layout menu logo etc.. after I saw this I told him I wasn't interested and to refund the money. He refused, and told me he would be able to sell it to someone else.
He is now trying to sell the design on dev art for 300$
http://www.j4yzk.deviantart.com/gallery/#/d2s26gw
Look familiar ?