What are your pet peeves?

If I get the bus, I find it offensive when people sitting at the back use the seat infront as a foot rest. God knows what they might have tread on outside and other people have to sit there. 

I don't mind if people eat on public transoprt, but I've seen people throw their empty food packaging either on the floor on on the seats. 

Oh, also people that spit in public view.