This is a good point. I'd imagine that if enough users cared about these sorts of privacy issues then traffic would end up declining enough that companies would have to either dismiss Facebook or Facebook would have to stop tracking users. I personally don't see that happening, except for maybe an uprising of a small minority of users. In which case we have to ask, does this stuff actually matter at all?

If most people don't care or are ignorant of whether they're being "tracked" then does it even matter?

I suppose that if this stuff matters to you, you'll have to just maintain a white-list of sites that you'll allow cookies for... hell, maybe it'll be up to the browser companies to bring this sort of issue to the forefront by touting the idea of cookies being disabled by default as a privacy feature.

Edit: Or maybe this issue is already being covered by some browser extensions a la Ghostery and the ilk. I guess it means that if you care enough about it, it's up to you to protect yourself.