Never, although I tend to ignore small fry in favour of the nastiest of the enemy team. I play TF2 and will often do my best to simply sneak around or plough through the other team just to get that spy/sniper/engineer who keeps taking my whole team out. Sometimes I'll even send them congratulatory messages if they pull off a beautiful headshot but I will hunt them down to my last breath before giving them an opportunity for another cheap kill.
TL;DR I tend to somewhat ignore weak players in favour of the stronger.
TL;DR I tend to somewhat ignore weak players in favour of the stronger.