At my times on forums ive seen a lot of ganging up. Whether its because of flame wars, scam or a rant ganging up on a person makes matters worse. So to those who do it, please stop as it not only hurts someone but it also ruins the play experience of the player. Sure, in a situation they might be breaking TOS or begging (or buying discounted items) but ganging up on someone is just as bad.
Those who are victims, i know what it feels like so i try to help them and even stand up for them. However lets not get carried away here, if the player is breaking TOS to the extreme eg. Buying/selling accounts, vile language, repeatedly breaking rules it is right to correct them and try to help, or if u dont really like the person, the mute and report buttons ur friend but dont gang up.
Its like being in a room, you are helpless and 3 people pointing a knife at you. You dont know how to get out nor can you defend yourself.
Ganging up is considered when 3-4 or more people troll and say negative comments on 1 helpless player / forumer.