A useless or pointless avatar, alias, or secret identity
Bill: Hey fuckface, we met together at John's BBQ and Bar yesterday, right?
*UtilityMan stops before he could finish beating Shrimp Scoundrel to death*
Bill: Dude, you need to drop that transparent mask of yours and just admit it. Everyone in Redwood City knows your real name and it's retarded to continue denying simple facts.