Ok, because of overwhelming demand, I'll tell the story one more time. It's well known in U2 circles, and has been independently confirmed, but for those who don't know it...
I was walking along the Grand Canal Docks in Dublin when I spied a group of street toughs doing a beat down on this skinny kid. I jumped in to help out, and together we fought the hooligans off. Kid thanked me and took off running, saying he was "late for a shoot." This being Dublin in the early 80's, I thought he meant shooting up heroin, but I found out later it was Larry Mullen, and he was on his way to the photo shoot for the October album cover that very day.
Anyway, if you look at his photo on the cover you can see the bruise under Larry's eye where one of the miscreants landed a right hook.
True story.