1.  Glitching- People playing Gears of War online love to exploit the game's issues by crab walking and using a shield along with a shotgun.  Makes me very angry while playing.

2.  Playing a mature game online as a little bratty kid-  I can't stand people under the age of 12 who get on Xbox Live and think that they're cool for screaming and annoying the crap out of everyone.

3.  Abandoning teammates-  This is especially bad in games like Left 4 Dead where cooperation is really important.  People will just run off and forget about everyone else in the game.

4.  Kill stealing-  This tactic will drive any gamer mad and it is especially common in Gears of War Execution which requires that you get close or use explosives to kill someone.

5.  Quitting a game-  This will ruin any team deathmatch because with an uneven amount of people on each team, it takes away the satisfaction of a victory or adds frustration.

6.  Always rushing for the power weapon-  Some matches feel like mini-races because instead of trying to kill each other, the winner is decided by which team has the rocket launcher and which team does not.

7.  Taking a game too seriously-  When you get too into a game which usually happens with a long amount of playtime or overconfidence, it not only makes you feel like crap but everyone else just finds you to be an annoying jerk. 

These are 7 things that people do (and sometimes even me) that will make the game I am playing less fun online.  Are there things not in the list that will anoy you that I forgot to mention?

Should be, ONLINE Gaming's Seven Deadly Sins.
Doesn't have the same ring to it, does it?

ONLINE GEARS OF WAR seven things that annoy OP is a more accurate title, but it doesn;t sound very good.

wow, you're hard core

8. Friendly Fire - whether it was on purpose or accident...but especially when it's for revenge for ur accidental friendly fire....that pisses me off...even after i apologize about the friend fire which alot of time isn't my fault because some idiot decides to jump in while i'm shooting the enemy just so that idiot can steal my kills...and what does he decide to do after he steals my kill...kill me as well...WTF???

Sounds like if you don't take #7 seriously you might not have a problem?

I'm going to get busy cooking but I'll reserve this spot for a better list of seven sins. in my opinion, you did not exploit the whole "sin thing" well enough

Lust: Thou shalt not harass women.

Women are getting into gaming. That's a great thing! A few years from now, you can actually go to a party and tell this one girl about your level 35 warlock! You can invite her home to play Brawl or mario kart. That is, if you asshats stop harassing women online. If a girl comes on a server, on live, or teamspeak you do not open with "OMG, it's a GIRL! Show us your bubs or ur not for realz!"Just treat her like one of the guys and you just might end up with a gaming girlfriend.

Gluttony: Thou shalt not camp

Or: Don't be a sniper. You all know this... hiding in a corner in a good spot where no-one can get you and score kill after kill. We have all been guilty of this. Just like we are all guilty of sometimes robbing the fridge of an entire pie. But under no circumstance make a habit out of it. Fight on the frontlines, and stay fit!

Greed: Thou shalt not kill-steal

Basicly, this is the guy that runs in while you are winning the firefight to score the last kill. Sometimes it happens on accident but really dude, how often are you sitting in the corner sucking on your thumb to wait for the right moment, full health, to chip away that last bit of health your teammates have so vigoriously fighting for?

Sloth: Thou shalt not be team-dependent to win

Again, don't be the sniper. Don't be the guy sitting in a corner occasionally headshotting a guy while you see the team is losing. If the team is losing, chances are you are doing a shitty job as a sniper or just plain hiding out hoping for the team to do the rest. Get your ass moving. Can't play the role you like, tough luck. Try soemthing else for a change.

Wrath: Thou shall mute thine headset when appropriate

Self-explanatory. When you feel the urge to cuss, shout, scream and let the anger out, leave us out of it. We don't want to hear you shrieking over why you just died and why it is unfair. Channel that anger. Use it to play better or, save us and quit.

Envy: I shall not covet another ones weapon

You lame ass P90 Noob! Why are there Grenade launchers in this game? Using the G36 is for pussy's! Sound familiair? that's because your jealous that the other guy chose a more appropriate weapon. Now shut up and play.

Pride: I shall not condemn my team

Or: You are not the teams savior and you are not all that. The rest of the team does not suck and you are not god's gift to the server. Despite your skills, it is still a game of luck and chances are that you are merely cussing out your team because the other team is better then you are. Now shut up, contribute and if you do it right you may have that pride rightiously so! 

I should have made my own thread, I think