The filters do indeed already exist, and have done for some time. They were originally (quietly) implemented by ISPs when the government made it clear that they

The filters do indeed already exist, and have done for some time. They were originally (quietly) implemented by ISPs when the government made it clear that they could cooperate, or they could have it made law and far more expensive to implement. The list of sites to block are currently maintained by the Internet Watch Foundation, with the aim of preventing access to child abuse, but could quite easily be expanded to cover other things. http://en.wikipedia.org/wiki/Cleanfeed_(content_blocking_system) http://en.wikipedia.org/wiki/Cleanfeed_(content_blocking_sys...