registered to an email address?

Yes...And have a look at this thread aswell for a more indepth answer http://www.legionworld.net/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=6;t=000214

Yeah. Each member has to have a unique e-mail address. The only exceptions are if we (Scott or I) create an ID from scratch. Even then we usually have asked for a new e-mail.

And as Joe-Boy points out, we have stopped people from signing up with multiple accounts.