West flew into a rage after he spotted the cards being flung onstage at Washington's Tacoma Dome, where he was performing with Jay-Z as part of their Watch the Throne tour.
He ordered the culprit to own up or otherwise he would have security kick out that entire section of the venue.
West told the audience, "I see it come from that direction… Unless one person raises their hand and says, 'I'm the one who did it', all that whole section gotta go."
West also slammed the mystery gig-goer for making their elaborate set dangerous by tossing the cards onto the stage.
He added, "We risking our lives up here, you can't go throwing s**t that we gonna slip on."
The rapper was relieved when the guilty fan came forward and was escorted from the show.