When we were coming back from Brussels just before Christmas 2010 in all the snow we got told that there were only 2 trains left and therefore the first 1400 people in the queue were the ones going home. There would be no more trains until after Christmas. We'd been queueing for about 5 hours and were about 8-900 in line.
A hundred of so back a British couple decided to push in to the line.
Security in Brussels train station was 4 very large men with 2 very large German Shepherds. Everyone standing in and around the jumper starting shouting and arguing until a couple of the guys turned up and lifted, and I mean that literally, the guy (who was arguing the toss) out of the queue. Cue cheers from hundreds of Brits who understand queue law.
I very rarely encounter queue jumping, most understand that it is just not on. Happens ALL THE TIME in the car though. Hey losers in the 20 car queue to go straight ahead, I'm going into this right right turn only lane and will accelerate hard when the lights flicker.