Reg banned word list:
USian? That doesn't even make syntactic sense. Yes, yes, I know you want to belittle citizens of the United States, and to harp on the fact that (North and South) America are continents, not nationalities, but, c'mon, you're not even trying.
For example-- have you ever encountered a Canadian who identifies themselves as American, because they share a continent with the USA? For that matter, have you ever encountered a German who identifies himself as European?
If you want something derogatory with which to reference US citizens, how about "Crazy ass yank" or "renegade colonials" or "right-wing continent squatting hillbillies"?
Personally, I don't particularly care; My interest is in the lameness being foisted upon the English language.
If you expand the abbreviation 'USian' to its logical interpretation, you're calling them "United Statesians," which I think we can all agree is just silly. It doesn't make you look witty, edgy, or urbane, it makes you look like you failed not only geography, but English, as well.
Basically, people who use stupid abbreviations such as this one are the intellectual equivalent to those who spell Microsoft with a dollar sign, "fanboi" as a contraction with the wrong vowel, and always use the hideously inoffensive "*nix" when talking about Linux in particular, and not the general class of UNIX based operating systems.
If you have a point to make, make it with the power of your own wit and intellect, not by flippant memes that only look cute to other morons.