And here's another "for instance":

Sometime during his second term Bill Clinton made a speech or comment using the word welsh or welsher. There was a public outcry by a group of Welsh-Americans (The Welsh-American League or something like that) who said it denigrated the Welsh and they demanded an apology which Clinton conceded to give. Oh, c'mon...

I've been using that word all my life as welch or welcher meaning reneging on a bet or promise, never having the slightest clue it ever had anything to do with the Welsh until this "controversy" erupted. It was just a word to me, and, as such, of course, carried no intention of insult or offense to anyone except for the deadbeat friend I directed it towards (usually in a joking manner). And I'm sure that the word, in either form, had become as generic to everyone else. Suddenly, it's on the PC list, because a small group, who probably don't represent or speak for all Welsh-Americans or the Welsh people, decided, after all this time, that it is now offensive.