I needed to post a support question to Electronic Arts support today (long story), and like many sites they force you to create an account.

Fine. So first things first I have to create a user account, and it's asking for a username.

dforbes...sorry that account name is already taken
dwforbes...sorry that account name is already taken
dennisforbes...sorry that account name is already taken
denniswforbes...sorry that account name is already taken
dennis.forbes...ILLEGAL CHARACTERS!
dennis_forbes...ILLEGAL CHARACTERS!
forbesdennis...sorry that account name is already taken
RRR...sorry that account name is already taken
blah...sorry that account name is already taken
blah999...sorry that account name is already taken
RRRRRRR999...taken

I'm not kidding. It was actually proposing ridiculous available alternatives for each, so I didn't have to keep trying, but at this point I was just punching in random strings to see how huge and polluted their database really is. It's big, and it's polluted.

These sorts of user accounts irritate me because I already have a globally unique account - my email address. No one else, in the whole wide world, has the same email address as I do. Furthermore I don't have to remember whatever oddball account you've forced me to take through arbitrary and site-unique username restrictions: Just use an email address and you can allow whatever is allowed in the RFC (it's all documented there for you), and when I get there I'll know what my username is. Why it's my email address! You're forcing me to enter it elsewhere to validate the account anyways, so you might as well go all the way with it.