Edit :: the stuff in the Sky blog post the article links to is pretty reasonable/shows it'll be (relatively) easy to use. People who complain are lol.
Like Platypus said, it's more of a worry as to where censorship stops. Torrent sites got blocked, which fair enough- they're illegal. Now porn sites are getting stopped which doesn't worry me as I don't use them.
Perhaps the next wave of censored sites will seem reasonable, and the ones after that- what would it take for you to get concerned? Blocking certain news outlets maybe? Or gaming sites 'to protect the children from wasting time so they can get on with their schoolwork'?
It's a long, slippery slope that seems reasonable until we reach the bottom. It's no good ignoring it and mocking people for being concerned - we should all be concerned about censorship.