As you know, Battlefield 3 beta on PC can support up to 64 players, compared to 24 players of the console version. There have been reports that some of the servers on the PC have been hacked, and now support 128 players!
Of course, it is not supported by DICE or EA, so these are unofficial and your EA account can be at risk. Gamers who played in those servers are experiencing lag and other issues, which is expected but only time will tell whether they will be completely fine to play without any issues.
We advice gamers not to play in these servers, as it is not worth it and you can lose your valuable EA account.