Nazi's

As I compile a blog on public diplomacy (and its problematical relationship to propaganda), why is it that I regularly see Nazi, when referred to in the plural, cited as Nazi's? Thats -- sorry, I meant that's -- one more example of my concern with Americans' inability (in a society that prides itself on its precision) to use the apostrophe correctly (a fact of life in the USA that is still a mystery to me). Please see (if you're at all interested) my piece on the subject.

At least this guy (below) can punctuate. No wonder hes an all-American nut with a whatyamacallit after about on his sign

-Image from