Naw, people do that at every single event. And usually when the singer gets to "land of the free" she decides she's gonna be a diva and hit an extra high note. Irritating. :-P
YOU KNOW WHAT REALLY GRINDS MY GEARS? PEOPLE WHO APPLAUD AT "LAND OF THE FREE" WHEN "THE STAR-SPANGLED BANNER" IS BEING SUNG; THE APPROPRIATE TIME TO APPLAUD IS WHEN THE SONG IS ACTUALLY OVER!