The whole point of this is to self regulate. If they don't put forms of regulation like this out on the internet then their will be many people who are very angry with them for not making this available so they are jumping the gun and trying to regulate themselves.

But really the people who will opt out are going to be a drop in the bucket compared to the masses that have no clue that this is even there.

(EDIT)If you want to see what data they actually know about you visit this site. http://tags.bluekai.com/registry