Which would again in my mind necessitate some kind of documented proof that you actually visited those sites, otherwise you'd simply be at the mercy of companies which could make up any old figure.
Not that I don't view intrusions against privacy seriously, or trust the government in any real way to deal responsibly and/or ethically with the information produced by me, it's just that at the end of the day I can't imagine that anyone actually cares about me or my particular surfing habits. I'd have to be active politically in an extreme and likely violent form, a child peadophile, hard drugs trafficker or.. well I can't really think of anything else that would warrant the attention necessary to start digging around in my files.
People have been against these things for years. ID cards aren't a new concept. People are routinely disgusted and have rallied against intrusions into privacy and issues of personal identity on and off for ever, but it will never stop any government or higher institution from trying to work out who you are. If these people really want to take the time out to pick through your garbage, they're going to to do it. Whether they're going to find anything useful is something else.