The U.S. State Department's America.gov website quotes Professor Mark Lemley on the growing number of copyright infringement cases brought on by the sale of counterfeit goods online:

“I think eBay is a model Internet company in terms of policing,” said Mark Lemley, a professor at Stanford University law school. “Like any copyright infringement, it’s impossible to catch them all. But you can set up systems to catch the most egregious players.”