Have you heard about Morganelli Group? It is a company dedicated to tracking digital contents in the network. The company’s mission is to protect digital products such as movies, games, applications from illegal distribution.
The company has set its sights on usenet. This is probably the first company that clearly said that usenet is a piracy haven and there is a treasure trove of copyrighted works.
Morganelli does not focus only on usenet. I think that they monitor the filesharing forums. From there, they probably know how many links to illegal content is available in the search engine Bing.
According to the September 2012 this company has sent more than one million DMCA notices. It is incredibly much. It seems that in addition to the BitTorrent network usenet slowly hit the top information on the fight against piracy.