The subject of blocking websites is a very difficult one. I note that in the United Kingdom, where they're just developing their Digital Economy Act strategy to deal with piracy, the first stage is to adopt notice and notice, and they're still mired in the details of how to actually develop a notice and notice system. But subsequent stages, I believe, contemplate blocking of content, and on that issue I understand that the government has actually referred the question to Ofcom, the regulator, to study whether it's even possible to do it effectively.
Blocking Internet content is very difficult to do, because it seems there are always ways to work around the blocks. There are always ways for sophisticated Internet users to find what they're looking for. And the very concept of blocking content runs so contrary to a lot of our other Internet policy values that it's just not something that has really been pursued.