If you behave differently on the internet it's most likely because of the anonymity if grants. In our real social lives, we have norms and social codes to follow. We cannot act like idiots because it will have consequences for us (like getting disliked, getting left out. Being seen as socially akward is not something we strive for). While this does apply to the internet, here the "norms" are usually very lax, and can totally differ from "IRL". Fear of exclusion is really what keeps people in check.
Now, this does not excuse asshattery. But if it's not noticed and reprimanded, it will spread and in the long run be seen as the norm.
What both of you are saying, between having extremes of yourselves and the anonymity that the internet grants there is truth in both, personally I am more or less just an extreme here of what I am in real life, I tend to see myself as arrogant, cocky and sarcastic but with decent morals and i'm rather self-righteous, here I have to say that more of the "morals & self-righteousness" comes out, time and time again I write posts that basically are "why can't we all just get along" and I have a deep hate for rule breakers (therefore morally superior) but on the other hand, I become far more of a narcassist online than in real life, I don't really care whos feelings I hurt if it betters myself and obviously, the ego!
But it doesn't give people an excuse to ditch common sense at the doorstep and do (and I don't know what exactly happened because I was away) whatever the hell they did, that's just idiotic in my opinion and when it comes to the point where this rule needs to be brought up again it makes me wonder why there are a few people out there that have to go to the extremes of the "negative personality traits" that we all have, one way or another.
There, another morality section there, but seriously, common sense people, it's even an official rule!!! Think before you do, these types of things shouldn't need to be prevented because they shouldn't happen.
