The only time I heard the expression "Plastic Paddy" used, it was in the context of an Irish native objecting to an Irish-American's opinions on the "troubles". I remember hearing "You sing Kevin Barry and Croppy Boy like they are pop tunes. We live it."

It had nothing to do with actually singing the songs. It was the inplication that the American singer was trivializing the situation in Ireland by pretending to be a militant supporter of all things Irish.

I have to admit. I agreed with the objection. Misty eyed singing of the Patriot Game by a bunch of drunks in a New York pub who have no idea of the history on both sides of the Irish troubles trivializes a complicated tragedy.