> I think the lack of "global" identities has dramatically hampered community migration and evolution.

Do you know what that sounds like? The "feature" that lets some credit card subscriptions follow you across credit cards although you'd like to get rid of them thank you very much.

I don't want a global identity for all communities I'm part of. Joe from the bait and tackle group (i don't fish, is that a plausible fishing group name?) has no business knowing what games I play unless I personally tell him.

Moreover, that nice store that gave the bait and tackle group a 10% discount has ABSOLUTELY NO BUSINESS chasing me in MMO #245768.