It's because it can track the where abouts of everyone. It's a massive privacy issue. Do you want the gov't to know where you go, what you spend your money, and who you associate with? I sure as hell don't even if they wouldn't find problem with it.
It really doesn't matter what the legislation says - no doubt they have already been doing and been calling it something else. It's going to be one of the worst things to come out of the 21st century.