It's based on a court decision where IFPI (association of record companies) sued Danish Internet providers, claiming that since illegal content could be downloaded from thepiratebay all access should be blocked. Unfortunately they won, meaning that I can't read this post (Well, I can, but non-tech savvy users can't) and that I can't get linux torrents, and other legal content.
Looking at the court case Google, youtube, and many other sites should also be blocked since they also give a user the possibility of locating and downloading illegal content. But I guess these targets are too big...
It's absolutely appalling and a clear breach of free speech.