I'm always skeptical of a legal solution to a technical problem, but I wonder how this is to keep me safe from trackers on foreign soil? Wouldn't these companies just move there server a country over? What if our ISP allowed us to block traffic from those who don't comply with the don't track header, would that solve our problem?
Excellent question. One solution for this would be to prohibit US-based first-parties from doing business with noncompliant third-parties (similar to what you propose, but doesn't cut across different layers, so less messy, less potential for abuse). It is similar to how some other laws work, and it would be up to the FTC to make this rule.
