While sometimes this is caused by total lack of PC skills and their windows account is called "admin", it is also used by little kids who want players on a server to think they are in control and not to be messed with.
Anyone who has been on a gaming server with over 30 random public players is bound to come across at least one. Some servers explicitly kick such players to avoid confusion.
(game chat example)
<<Senior_Admin is connecting>>
Player 1>> OK STFU about that hack, admin is here
Player 2>> Its just an admin Wannabe you noob
<<Senior_Admin was auto-kicked: Remove 'admin' from avatar name>>
Does not include the following examples:
as they are clearly not trying to imitate an admin, but will still get bot kicked