I guess most folks in this discussion are missing the big picture.
Yes, we all know ads are the way to keep certain services alive as “free”.
Yes, we all know sites want to know more about you to offer you ads on what your interests are.
Yes, we all know sites such as Facebook and Google’s AdSense go greater lengths to collect information about your interests, including outside their own services.
Yes, we all know these two aforementioned services do sell your data to other companies as packages for targeting audience.
The questions are, is it illegal to run ads? No. Is it illegal to harvest data on you? No. Is it illegal to sell your data without your consent? No. Is it wrong to want to opt out from this massive data harvest and personal data sell? No.
Just like the “do not call” database, except these companies gives a rats ass to the “do not track”, and could care less since there’s no “do not resell me”.