je pplz did some great work to track users even if they have dynamic ip.
in the end, this times are anyways over soon. all games of today have a global user id.
beeing anonymous mean to go to shop every day and buy new account.
and ipv6 stands in front of the door. there will be still the classic anonymity (user identity protected by provider). but the people have the possibility to start reachable servers, i think they will call it then web 3.0 or 3000