My first reaction was from a slightly different perspective, as the wording of the comment made me wonder why both first and second world citizens were excluded.
I said "
3rd world cities" because, silly boy... There's New York, and there are 3rd world cities!
But, seriously, I could have said something more recognizably humorous, e.g. stolen a line from Gilda Radner and said "
can go back to New Jersey," but some of the 3rd world cities would probably have found that insulting.
Edit: OK...
"3rd world" cities would have been clearer; sorry for being obscure.