Reminds me on the old Commodore 64 Quantum-Link service (former version of AOL), there was a hack called 'Q-Armor' where you could get a username of all spaces, and no sysops or any chat room managers could kick you, or do anything to your account.
For some time you could steal AOL usernames by registering i.e. 'obar' or 'oobar', and using client side hacks could switch the registration to the already registered username 'foobar' which would then belong to you.
This only worked if 'obar' or 'oobar' was unregistered, but it was a pretty nifty way to steal single word usernames, and speaks to some strange validation/truncation somewhere in the code.
In the StarCraft community these are known as "barcode users". They often tend to be professional players on another account, to ensure that they aren't recognised and their opponents can't learn their playstyle.
I used to use aim chat booters by a blog named 'esoteric code' program was called subterfuge. Familiar with it by any chance? I thought it was brilliant.
