I actually ran into almost an entire party of boosters sometime last month in the FFA playlist.
It was incredibly fun since it pretty much turned int 5v1 while I kept mowing them down. Did this for about 5 matches before losing connection to the lobby.
Happened to me in MW2. Ran around with a Silenced Striker (one of my favorite weapon combos from that game). Kept hearing things like "WTF!?" "I thought everyone was boosting!?" and my personal favorite, "Who runs around with a silenced striker anyway?"
"Gary was here. Ash is a loser!" = Greatest Tramp Stamp Ever
Yeah, how dare you boosters play the game the way you wanna play it when you only paid for the game. You should be forced to no life it and rank legit - like the rest of the peeps with tons of free time who do nothing else but play CoD...