As we've seen from the unfolding NSA scandal, the line between identifiable data and anonymous data is not always clear. Remember how "metadata" was supposed to be this thing that was anonymous and could not be used to identify anyone?
I understand what you're saying, but the ability to identify someone from a discrete set of behavioral data is a moving target. And proving when a company has actually "identified" you as you and not as a set of your behaviors is going to be very tough.
The only approach to this that has any merit in my opinion is figuring out ways to salt your data with phony data. I remember there was some talk about a project to have a browser extension sent random crap to trackers. I like that idea. At this point, protecting my privacy isn't enough. I want anyone who wants to take it away to get messed up.