I have spent the better part of my life, it seems, writing letters to the editor and occasionally newspaper articles. Never once, during all those years did I ever think twice about the publications' policies requiring the use of the writer's real name. My reasoning is, if I have something worthwhile to say, I will stand behind it with my identity disclosed.
On the Internet, however, these requirements do no seem to apply, as newspapers and other publications with readers' forums allow for the use of pseudonyms, an identity-concealing facility I have never availed myself of.
Judging by any perusal of such sites, however, it is readily apparent that anonymity frequently lowers the level of discourse to mere sniping and hate-mongering. With rare exceptions I have stopped, for example, reading the comments following Globe articles, as the first few may be insightful, but what invariably ensues are attacks on the constructive commentator's politics or intelligence. The term used to describe such attackers is trolls.
Alternet, one of my favorite alternative news and commentary sites, has an interesting article entitled Why Online Comments Are So Toxic. Written by Lisa Selin Davis, it is well-worth reading.