I saw Alien when it first came out. At the Hollywood Egyptian Theater. Odd theater, the projection booth is low, so the center isle jogs around it. On the second turn I abruptly turned around, shoved my spread hand into the face of the stranger behind me and screamed eeeahh!!!
Turned out to be a black kid, he visibly blanched and said in a quavering voice, "Don't DO that, man!!!
He's probably still trying to find me...
Oh man. Heart attack time. You'd get sued for that these days ;)