Uh a privacy nightmare (giving out your identity to a random, unaccountable company to be able to play a game? Yay what a splendid idea!) and perfect recipe for

Uh a privacy nightmare (giving out your identity to a random, unaccountable company to be able to play a game? Yay what a splendid idea!) and perfect recipe for killing the game, because now you aren't punishing cheaters but anyone who is playing better than the others (for whatever reason). So players are actually motivated to play at a mediocre/average level instead of trying to get better, because then they could stick out of the crowd and get punished/hassled. What a wonderful thing to incentivize ... facepalm