That's one of my pet peeves, and so I can tell within seconds if someone snatches even so much of a glance over my shoulder.
I take a change and look up at who might be reading my anthropology textbook. A young man with blonde hair is looking over the seat behind me.
"Hi," he says, "Don't mind me, I was just reading..."
I expect him to finish "...over your shoulder." But he doesn't. That makes me really nervous. Why would he want to read my book about genes anyway?
That goes on for a few minutes, because obviously to this guy there is nothing at all weird about reading over a random stranger's shoulder. Finally I can't take it--and no reading is getting done anyway--so I close my book and call my mom.
The same guy makes conversation with a man across the aisle about Dr. Pepper. "That would make good rocket fuel." (?) he says. The older man takes a swig and says, "It makes a great thirst quencher."
I was happy that this talkative character got off at the first stop.