If you aren't bothered then your portion goes to everyone else. If only one person signs up they get it all. If you don't register you are still involved as the class action and US Law means you give up your right to file a claim ever in the future for the same offenses. Only way to be able to is to write the courts requesting to be excluded.

In short it's happening so they can buy me a burger cause I'm never going to do anything about it.