sorry bout doublepost - the guy not playing ANY multiplayer games sort of explains why he isn't recognized by google.. even with rather poor compatibility with flash, google should manage to see the in-game links to profile pages as well..

Except there is no list of all games either (your reasoning would work for ladder games; depending on how often the dashboard gets spidered Google should have a pretty complete list of all ladder games).
Sure, you could just iterate over the game IDs but (to the best of my knowledge) Google doesn't even attempt that (and, to be honest, I'm not so sure if I'd want them to do that).

Still wondering how Clacko found it... because (unlike game IDs) player IDs are not consecutive, so he didn't just iterate through them all.