Just a few minutes ago, I had a run-in with a couple of boosters... in Domination. The one that was actually getting boosted was on my team the first round, and he got an 83 and 3 KDR, ending the game with a Tactical Nuke. Next round, I saw the amout of deaths his partner (who was on my team) had, and it matched up exactly to the amount of kills the first guy had. Thankfully, the cohort was a total tool, and was constantly breathing in his mic, so he was easy to find and follow. I stopped the guy short by cutting in with my FAL, and then when they relocated, I just followed the tool to the shack and watched for a moment, then threw a semtex in and killed the both of them. Eventually, the idiot tried to evade me, even going as far as to throw smoke grenades at me (and knifing/shooting at me, although friendly fire was obviously off). It was cute, but retarded. Needless to say, they both ragequit right after.
My question to you is: In what gametypes have you found boosters, and how did you deal with them?