The other night I was playing MW2 and for whatever the case, this other player obviously was not in a very happy mood.  And the only reason I could tell was because he sent me a voice message stating that "I was the worst Call of Duty player he had, honestly, ever seen" and that my choice of weapon didn't take much skill to wield.  So, needless too say, he wasn't happy with me. 
                    Now, I understand his point because I've been on that side of the fenceline too.  I've had my off days where I wanted to send messages for stupid things like that. And I've had my on days where I "cream" almost everyone in the match.  And while I get that he needed to vent his energy, there's still a line that shouldn't be crossed.  Now, if I had been "camping" in one particular spot and was getting a kill every time, yeah, I could see getting ticked.  But, just because his skills weren't up to par for that particular day or round, doesn't mean that I'm automatically to blame; or even that I was using a particuular secondary weapon.  But, his lack of skill is still, HIS lack of skill.  In no way is it my fault.  It's the idea of taking responsibility/ being accountable for your own actions. 
                   If you screw up at work, it's on you.  It's no one else's fault.  It's...YOURS.  And this is what irritates me the most; is that people don't take responsibility for their actions.  They'd rather play the "Blame Game" and never settle the issue. 
                       When Samuel told King Saul to kill every living thing when they destroyed the town of the Amalekites, and later came by to see how Saul was doing, he asked Saul, "What is this bleating of sheep in my ear...?".  What did Saul do?  He blamed it on the people as to why the sheep were still alive, so that they could sacrifice the best of the sheep and other animals to the Lord.  And for that mistake, Samuel told Saul that the kingdom which he was given, would be ripped from him and given to his neighbor(David). 
                        Now, we may not have an entire kingdom ripped away from us for doing such things, but at least part of the idea still stands: If we don't take responsibility for our actions now, we WILL pay for them later.