The whole success of snopes is dependent on their accuracy. The reason people use it is because of their reputation, therefore it is in their best interest to be as accurate as possible. Obviously they are human and make mistakes, but if they would continuously make mistakes people would start catching them and they’d be out of business. Therefore they spend money trying to accurately research their info.
mbachur — snopes is a sight that attempts to verify the accuracy (or non accuracy!) of rumors, stories, urban legends, etc.