Although it's quite annoying at times, or many times, as long as I get to play my way and they get to play their way, all is good.
What I do: (Just go pyro and air-blast them into the air, finishing them off with the reserve shooter in 2 shots)
For other classes, just be distant of course.
If you're stuck in a corner or inclosed space, well just start praying at that point.