I'm not always the tallest in the room when everyone is standing, but once we're all sitting down, I'm the only one sticking up above everybody.
Normally when I'm sitting in a theater, I do everything I can to avoid blocking someone's view (slouching, sliding down in the chair, leaning, etc). It ends up being incredibly uncomfortable.
One time a friend gave me and my wife tickets to a show (live musical theater). There were a couple drunk, obnoxious women behind us talking through the show. It pissed me off so much I sat up straight in my seat and stayed that way for the rest of the show. It's the only time I've ever done that.
They started complaining about me blocking their view, and left during intermission to complain to someone (what did they expect the theater manager to do? "Excuse me, me sir, but you're blocking these 'ladies' view. Would you mind removing your head?'). They eventually returned to their seats.
By the time the show ended and people stood up to leave, I was pretty angry. I turned around. I don't know what I was planning to do. It's not like I'm going to beat some drunken idiots to death in a crowded theater. However, I know I was considering stepping over my seat to get into their row.
The older woman was too drunk to notice, but the younger one was sober enough to see the look on my face. She hustled them out.
My wife has told me that I've terrified people even when she confirmed I was being perfectly calm. I can't imagine how frightening it is when I'm actually enraged.