Each person is allowed to have one member registration. You may not have more than one member name. If you create more than one member name, your second name will be automatically revoked, and chances are very likely that you yourself will be banned from MousePad forever.
You may not think this is a big deal, but we believe this has to do with each individual's integrity. We take a very dim view of anyone pretending to have a friend to back up their views in a debate.
The term used to refer to additional member names by the same individual is "sock puppet."