Technology Review has a nice article on video sharing services and piracy:

Pirated video makes up about one-fifth of the moving-image content uploaded to video-sharing sites, according to Tom McInerney, founder and CEO of San Francisco-based Guba. And while the sharing sites benefit indirectly from pirated videos, which generate Web traffic and advertising impressions, hosting this material is often more trouble than it’s worth.

Considering that only “YouTube visitors upload 65,000 videos every day and download 100 million of them”, it is not that bad, isn’t it?