Credit: Jon Kopaloff/FilmMagic; Kevin Mazur/

Deadmau5 may wear a mask, but he's hardly hiding behind it.

The 31-year-old electronic music producer -- real name Joel Zimmerman -- lashed out at Madonna on his Facebook page after the pop icon, 53, took to the stage to introduce electro artist Avicii at Miami's Ultra Music Festival Saturday night.

According to concertgoers, Madonna addressed the cheering crowd, asking, "How many people in this crowd have seen Molly?" ("Molly" is a term used to refer to MDMA, one of the drug ecstasy's main ingredients.)

Deadmau5 wasn't amused and vented to his Facebook followers later that weekend. "Very classy there Madonna," he blogged. "'HUR DUR HAS ANYONE SEEN MOLLY?' Such a great message for the young music lovers at Ultra."

The music producer's rant didn't end there. "I can appreciate [Madonna's] metoric career, and all good deeds done, but WHAT THE F--- WAS THAT?...That's your big message to Ultra attendees? Hipsterspeak for looking for drugs? F--- off you f---ing IDIOT."

"Quite the f'in philanthropist," he continued. "Can't smack my head hard enough right now."

Deadmau5's fans pointed out that the singer may have been attempting to reference her new album -- MDNA -- but that didn't seem to satisfy him. "Still seems the same to me...MDNA/Molly/MDMA/whatever...something about a track?"