saw this posted on another board...

I'm guessing you meant to say "to call citizens of the US 'Americans'..."

and that's completely wrong.

Blacks are not usually black
African-Americans are not necessarily African or (according to some people) American
anti-Semitism does not refer to bias against all Semitic races

etc.

those terms, like American, are cultural constructs which have a real meaning that is more important than their literal meaning.