I think there was a psychological study some years ago which said that when people are hiding behind the anonymity of the keyboard and monitor that they will vent their rage much more easily. I think that is very true, but additionally I have been a FREQUENT victim of Office Rage myself, and there are a lot of people who feel free to vent their rage in person too. And even more so on the road, there's no shortage of Road Rage these days. I hope that one day we can eliminate SUV's in our lifetime. Why can't Detroit design something that is much more aerodynamically practical, and burns fuel very efficiently, so that we can all go out to buy groceries in something more like a Le Mans prototype car, or a snappy foreign model with a name like Formel Eine!?
I think internet forums will always be very emotionally volatile until society matures with this technology. There's one person who even today was blogging with hostility. Some people may have more than just Forum Rage they might have a deeper psychological problem. On the other hand they might just be mean spirited, with little tolerance to questions that are beneath them.
Or perhaps we should just go with the flow and change the "Post message" button with, "Post your FORUM RAGE NOW!"