It isn't like they have time to watch every person who downloads something.
HAHAHAHAHAHHAAHAHAAa
I am sorry but for all you "England Prevails, down with the USA" jagg-offs I must say that every time I read news like this it reminds me of V For Vendetta.
bottom line is that this leaves the door open for interpretation. Meaning they can flag all sorts of URLs and deem them "illegal" just as the proxy here at my work does. Now some of the sites I go to I know don't have illegal content on them however can be home to illegal material (like file storage sites), but I am still flagged when I click on a link to someone's image or demo that is hosted at that site which is 'known to house illegal material'.
Good luck to you all if this goes through. Your going to find yourself on the telephone to your ISP very often as you have to constantly and consistently explain why your pop-up blocker didn't stop that one window to that illegal warez site.