'Bono was really mad': The man who stopped a U2 gig with a sign

Bono on stage at Páirc Uí Chaoimh, Cork, in the same year U2 played in San Francisco. 

On a quiet Wednesday morning in San Francisco in 1987, Robert Quinn was at home listening to a local radio station.

The young graphic designer was eager to catch a glimpse of the hottest rock band in town that week as U2 were due to play two sold-out shows in the coming days — the Joshua Tree tour was not to be missed.