Joan Rivers to Anti-Defamation League -- 'Shut the F**k Up!'

Joan Rivers is scoffing at the Anti-Defamation League for blasting her over a comment comparing Costco to Nazi Germany, telling ADL officials, "Shut the f**k up!"

The ADL is pissed that Joan made the comparison to protest the fact that Costco banned her book, "I Hate Everyone ... Starting With Me!" because of foul language. ADL officials say, "Such comparisons only serve to trivialize the Holocaust and are deeply offensive to Jews and other survivors."

But Joan -- a Jew -- tells TMZ, "My husband lost his entire family in the Holocaust," adding, "My comment reminds people of the Holocaust because half the people now don't even believe it ever happened."

Joan adds, "Germany is where banning books started, and it can start here just as quickly."

And Joan made this obtuse comment, "I'm educated. I know how to spell Nazi."