I see that McAfee has filed a patent on some new kind of Site Blocking Technology. They filed it in October, 2012, but it's just been made public.
The goal is to have a McAfee-version of DRM, apparently - they will intercept URLs, transfer them to another server, match that against a list of all banned URLs and then deny or allow McAfee customers to go forth and...
The matching-servers will look for sites that distribute copy-protected data streams.
"It's not censuring the Internet," is the McAfee claim.
Was it Frank Burns or Adolf that said, "I'm not burning books. I'm just testing gasoline and matches in this barrel - the books just happen to be in there"?