I can't imagine eBay is too terribly interested to lead a "War on Fraud" because of the potential damage to their business. In this is respect, eBay is a lot like a credit card company. If they crack down on fraud too hard they stand to lose serious money because A. Nobody wants to do business with a bunch of people who all have 48% or 32% or 68% approval ratings and B. Barriers to fraud and bad users are also barriers to ease of use and approachability of the service.
Better to set up a fraud dept., accept a certain amount of lossage/settlements as part of doing business and let users continue to be {altru|optim}istic about each other.