First come first served.
If you want to be TheNewGuy all over the interwebs, I suggest that you spend the next 10 years searching out all possible discussion boards and registering as TheNewGuy.
After that, at some point, someone will pipe up on some random board, lets say Ferret-Keeping-Online, that some usurper on another board, lets call it AllAboutFerrets, is calling himself TheNewGuy!
JimB
(One of many JimBs to be found on the interweb computer thingy).