Wow, thanks for all of your replies!
To NeoMaxiZoomDweebie I apologise if my posting here is against the rules. I recently received new guidelines from the Mumsnet Bloggers network (to which I belong) which stated the Mumsnet bloggers are allowed to share posts in the chat forums. I respect your choice not to participate in this discussion, however.
To Mis 4 I agree, sometimes there's a "sheep" mentality and people do jump on the bandwagon. It doesn't say much about humanity really. In this case there was no question about the bullying, but I do agree that on occasion people "cry bully" when the truth hurts. Not helpful to anyone really.
To StephenFrySaidSo... No, honesty isn't a new thing. Perhaps "arrived at a time" wasn't the best use of words. I just see more and more Internet cruelty (or at least, unkindness) on a daily basis. I believe the more we raise our voices against it, the quieter their voices will become.
To FirmYoungCarrot, yes, sadly people have always been like this. The Internet just seems to give a louder soapbox (can a soapbox be louder?!) and I worry about where it will take us next.
To Bebanjo Cyberbullying is easy to avoid in theory, but at the same time damage can be done very quicky. Especially when we're talking about brand new mums who are unsure of themselves to start with. The thread was eventually deleted, but unfortunately the hurt it caused her can't be undone so easily.
snoopingforsoup, I've said before that if every fleeting thought I had was made public I'd probably be institutionalised! And I'm sure Anna will think long and hard before sharing her thoughts again. Lesson learned there, I guess.
lilithtime I didn't share the original question because firstly I didn't want to open her up to further abuse and secondly I felt it would detract from the point. There was no question that it was ill advised and would've put her LO safety at risk. But she quickly apologised. If it was my own mistake I'd blurt it out online like I usually do, but in this case it's not.
jacks365 I think if we saw something in real life putting children in danger we should absolutely speak up. A friend recently stood by a car with two stranger's children locked I'm it for twenty minutes before eventually calling the police, as she was afraid for their safety. In this case Anna had a misguided thought which she shouldn't have shared and it went berserk.