I've got another helpful idea:
Since server tracking for online buddies are possible, and we all know all RTB Servers can show what players are in their server, and that non-RTB servers cannot what players they have in the server list, I propose the idea of finding RTB players in a non-RTB server, and therefore, we can see who RTB users are in a certain server, even if it was RTB-powered or not.
Kinda useful if you want to check out who's in the server.