I think it's pretty straightforward, Helnar.
You don't say or do things because you know that there are social repercussions. My boss is rude to my coworkers, but I don't say anything because I could get fired.
Remove the social repercussions (via anonymity) and you have no reason not to do those things. All of a sudden I can verbally abuse my boss as much as I want.
Doesn't mean someone is socially dysfunctional, it just means they're free to say exactly what they want to say without any inhibitions.
No, it just means that your boss is just as social dysfunctional as the guy who lacks any civil courage to stand up against that dork. Ok, maybe your boss is a little more dysfunctional.
It's a very interesting phenomenon when people start judging others based on little or no information on the internet, even though all of the needed information is right there in front of them.
I'm a psychologist by profession, yet I still haven't fully digested why some people become rude and inconsiderate (trolls) when they are nameless and behind the screen. Why? Because I don't care for explanations about the "dark side" of human nature. I think it must stem from a lack of self esteem, or the need to "rise above the pack," so to speak, by putting someone else down (the need to feel superior).
I any case, there is either something "not right" regarding their social development, or they are in that critical stage when social development is rapid but fragile and can easily swing one way or the other (teenagers). If you guys happen to read this, I suggest you try to explore why you act this way, and if no answer comes to mind, talk to someone about it.
Riot is still doing intensive research on the topic, but I think the most common explanation is feedback loops, because the amount of contacts with other people you have is extremely high and the consequences for bad behavior are extremely low.
A single person that fits your mentioned types is enough to make dozens of other people grumpy as well and so it spreads all over the world. Besides that: There seems to be a significant number of people with sadistic, sociopathic or psychopathic tendencies involved in trolling as well. And again, a single of those can be the catalyst for many more angry posts from other persons.
