We don't know what you're talking about. Do we? No, we don't. See, I don't have multiple personalities. (and neither do I) :happy102
No one here has multiple log-in/usernames for TSD. However, they may have different usernames at each of the different forums.
Generally speaking, one person using multiple names is up to no good. It is possible to do, but the forum has built in protection that will eventually correctly identify them, and then close both accounts. This is all done automatically, without any intervention from staff.