"Troll cries make MNers look silly. If you think the person is not real, you don't have to post - nobody has a gun at your head! If you suspect the person is false and trying to hurt, or get money, tell MNHQ! How terrible if genuine people - people in trouble, people at the end of their tether - come here as their last hope for some help and advice, are savaged and go off again, feeling terrible and that they don't have anywhere left to turn to?"
www.mumsnet.com/info/netiquette
There is a very real problem on Mumsnet that there are a small group of posters who wilfully ignore this "rule" as and when it suits them. I think the problem is now institutionalised in MN as being the norm and acceptable.
These people just make stuff up about people they've never met. Once they do this other people pile in believing the bullshit, and then acting on it. The troll-hunters also don't seem to stop and think how their assumptions might affect - or even damage the rest of the site. Lets summarise their position: " I am OUTRAGED and APPALLED by something that may or may not have happened but can't be proved, because although I say it did, I won't provide any evidence"
Sometimes this place is more like a bear pit rather than a community of support and OBJECTIVE thinking and response.
They have their bit of fun and when their target gives up - off course they do having been hounded unmercifully - the Hunter claim that proves they were a troll. Disagree with the unters and sooner rather than later they will accuse you of being a man (their ultimate insult) or a troll. A suggestion that you should leave the site usually follows.
The "silent majority" don't put up with this. They just leave...