What he did (in game) was very simple. There's this PvP zone, Heroes come from one side, Villains come from the other side. Each side is protected by instant-kill bots/drones, like any other mmorpg, certain areas are protected by bots so enemies (PvE or PvP) don't come to close, to protect the lower level players or who just appeared.
Apparently he sat close to one of his faction's drone, targetted an enemy player, and teleported the enemy close to him, causing an instant drone kill.
Now, something like this happening once or twice is a PITA, but the article gives the impression that he did to several players, in the course of many, many weeks. It was probably very boring for him too, since drone kills usually don't give any reward.
What I find strange, the whole thing is a textbook example of griefing, and the CoH/V admins didn't do anything to stop him. Sure, it was inside the game mechanics, but a complete distortion of any intended PvP design.
Also, a little map rearrangement or some kind of "when teleported by an enemy, the player is immune to drone kills during 10 seconds" power change should have stopped this form of griefing completely.
Which makes me think, if the admins and devs didn't do anything, this whole thing was way less destructive than the professor wants us to believe. Either not much people complained, or he did stop when/if an admin asked him to.
If someone farts in your face repeatedly and you go on to punch them or harass them in any way that is considered inappropriate by society, would you say that your actions were 'justified?' To me, that would seem rather biblical, in the negative sense: eye for an eye, tooth for a tooth.
So the point is: we're still in the biblical era of social behaviour: if someone harasses us, we harass back. Though I wouldn't know how to respond 'properly' and in a 'civilized' fashion to such a situation, even though I'm an online gamer myself. In WoW, there's the anti-social practice of 'corpse-camping' someone, and thus killing them repeatedly. In such cases I just log off and play an alt, and let the camper waste his time.
Call me "biblical," but where I'm from farting in a grown man's face will get you punched in your own face, repeatedly, in a highly civilized manner.
[edit: formatting]
Also, "medieval behavior" would be actual, physical harm. I think it's worth noting that no one escalated it beyond the online realm.
I am pretty sure I could obtain a legally binding restraining order against someone who kept doing this to me.
Prof Myers found an environment where he was safe from punishment, and started griefing. People got mad.
Wow, annoy people and they get mad. Great study. You've really advanced science with this one!
The strange thing is that in this account (which I hope is misrepresented) the researcher seems surprised that violating the social norm got him a hostile reaction.
http://archive.thenorthernecho.co.uk/2004/5/3/53732.html is the best link I could find quickly.
An simple example. I´m from Brazil (sorry by my poor english) ... and i play World of Warcraft as well. On the game, one of the social rules (no legal rules) is to talk in english. No problem. We do our best and it´s good to practice another language sometimes. BUT ... when we meet other brazilian folks and start talking in portuguese close to american guys ... all the hell start. They (not everybody off course) tend to offend us, our country and start saying a lot of bad things of us. We don´t take it personal, most part of the time, but it´s very weird because the tolerance to out of box things (like another idioms) and the treatment to those who make things in the "wrong" way is far too bad. I´m not saying that the scientist was correct, even us who talks in portuguese, but the reaction and the self control of the average human still being to naive. And, i think, he proves it very well.
People takes things too personally. From the article, I never got the sense that the Professor was taking this personally (he shouldn't, he is conducting a study). He wasn't deliberately aggravating other people: he was ignoring the social customs.
In you and your friends case, it is even more ambiguous. What you do doesn't directly harm someone, neither physically in the real world, or virtually in WoW. And as you said, you don't take it personally ... it seems though, a number of people do.
Wait wait - so he knowingly violated all social norms, despite gentle attempts to correct him, and that proves there is an ugly side to fantasyland? It would have been more interesting if he had done something non-mainstream that did not impact on other players and seen if it would have gotten any abuse.
After all this is the essence of tolerance in real life - nobody expects you to be tolerant towards people who are shooting you; tolerance comes from a "live and let live" approach. Investigating the equivalent of that online would have been interesting, but it is not what he did here.
What he did here was the equivalent of say, farting in your face because it is "within the rules" (i.e. not illegal) and then act surprised when this made him socially excluded.