[jnky]

I disagree that the "Do-Not-Track header is a perfect solution to this", because it implies that the default (i.e. the header being absent) should allow sites to track you. I (and apparently EU legislators) think opting in to privacy is wrong. You should have privacy by default. If anything, there should be a "Creepily-Track-My-Activity-Over-The-Entire-Internet" header, that, when present, allows tracking.

There also used to be another standard called "P3P" that tried to integrate privacy into browser UIs with a more or less standardized interface and that, too, failed. Among other reasons because companies wanting to track people subverted it.