If you are going to "snipe" (and by that, i mean the assumed definition, which see above for my disagreements), I recommend going in pairs. I always think of myself as a fox, and I don't want to get into a hole I can't get out of. My friend and I usually find guys who try this and simply send one of us to the other side and trap him while I find a couple of willing souls to drive him out. As the rooster flies the coop, we trap him. A second player can prevent this from happening, and also allow you to pullback. If you are REALLY good, you can make it look as though it was him doing the dirty work and thus they aren't expecting someone else. All a mind game.
One final thing: it was Gunnery Sergeant Hathcock...he was promoted towards the end of his career i believe.
For as I walk through the Valley Of The Shadow Of Death I fear no evil; For I am the Shadow of Death and evil must fear me.
"Get your facts first, and then you can distort them as much as you please." - Mark Twain