I blame griefing on the people who play. There are certain strategies that must be employed with online >team based< games. Running and gunning solo is not one of them. A lot of the times, you are trying to do something, e.g. baiting a mech into a trap in Battlefield 2142, and right before you succeed one of your dumbass teammates gives away your position. GGGGGG-GGGGGG-GGGGGGGGGGGGGGGGGGGGGG. Dust. You're now a corpse. That teammate somehow flees the scene unscathed. God damn teammates.
Certain game mechanics demand certain behaviors and people are too damned stupid outside of clans/guilds/etc to implement them properly. This is why I grief. If no one wants to play a team game as a team I am damned set on either disrupting the strategies of either the enemy team or my team by any means necessary. Depends on how bad my team is really. If my team is team retard (you know, teammates running the opposite direction of the objective, unable to identify friend from foe, constantly jumping in front of your shot and bitching about you shooting them), I'll probably grief my team, although generally focusing on the "problems". This is nothing but punishment for their stupidity. Note though: I generally do not target the "noobs" who are new to the game. It's kind of obvious running into them, such as driving a tank off a sudden cliff that everyone else knows about. They are hilarious in their own right. And also really easy to avoid if you are planning something strategic.
However, if the enemy team is just stacked horribly against our own, I'll grief them in hopes to balance things out a bit while they focus their wrath on me alone. Team based games cannot be won by a solo player if the enemies are well organized. I'll admit it, I am not a god at these games, hell I'm usually just your average player. But if it's a bloody team game, I'll, oh I don't know, try to play as a team.
If at the start of the round all the douchebags, you know who you are, switch to the same team just to upset the balance, oh ho ho, the griefing is on big time. Clannies are big time offenders of this. Team games should have *SOME* balance to it. One sided games are not fun for the losing team. You are griefing by your own skill gained by your sheer lack of social skills cave dwellers. Do everyone a favor: if your team is consistently winning, and you are one of the best players on the server, join the other team and give them hope. Not only do you get challenge WHICH I HOPE YOU WANTED but you can teach the lesser skilled the ropes to total pwnage... or whatever you folk call it these days. If you just decided to play so that you can all get 20-1 k/d ratio and rub it in the lesser players' faces, well, piss off griefers.
If things are going well in a game, or is balanced, if I am not playing like everyone else, I generally dick around to almost no harm to any player, such as getting on top of buildings you aren't supposed to and firing single shots of my pistol at unsuspecting enemies clustering below. It's hilarious watching them try to find who is shooting at them! Even better when they teamkill each other due to some lingering internal team conflict. Sure I'm not helping my team all that much, but the game is balanced at this point of time. Most people *should* be having some sort of fun at this time.
whew. End of rant!