Feminism has been such a success that I seldom have cause to think about why it's so necessary. Sure, there is the occasional reminder - it was the 61st Miss World in London on 6 November, because women's opinions are much more interesting if they're wearing an evening gown - but I have a job, a vote and the choice of when and if to have children. I'm part of the luckiest generation of British women ever to have lived.

In the past few days, however, I've had a pretty revealing glimpse of a place where casual sexism and just plain woman-hating still exists: internet comment threads. On 3 November, I published a post on the New Statesman website in which nine female bloggers described the kind of threats they routinely face in comments and emails, and on other websites.

Every flavour of low-grade yuckiness was there - you're ugly, you're fat, no man would want you, no one cares what you think - but there was also a large slice of something much more sinister. The feminist activist Kate Smurthwaite was told that someone should rip her tongue out "of her suckhole". Cath Elliott, a freelance writer, was told she was "too ugly to rape". The London Evening Standard columnist Rosamund Urwin heard that she deserved to have her fingers cut off. And, in a catalogue of threats of sexual violence, Caroline Farrow, a religious blogger and former vicar's wife, said she was often informed that "people would deign to have sex with me either out of pity or to teach me a lesson". Occasionally, writers reported receiving emails with their personal details included, or photos taken from Facebook.

The blog post had a huge response, with dozens of women getting in touch to say they had faced much the same kind of comments - and dozens of men saying they had no idea the problem was so widespread. My worry is that such relentless, remorseless abuse is discouraging a generation of women from writing on the web. One established female columnist agreed that she might have given up early in her career, had she faced similar abuse.

It's nice that people are talking about this, but what next? I hope that all the women who had been suffering in silence now realise they aren't alone. I hope website bosses will ask themselves if they want to host this stuff. And I hope that the police will take such threats more seriously. Petra Davis, who used to blog about sex, told me: "When I started getting letters at my flat, I reported them to the police, but they advised me to stop writing provocative material." Oh, and on a personal note, I wish that any man who thinks we're all whining little flowers would post an article under a female pseudonym. It would be an education.

Share alike

There is one subject on which my opinion sharply diverges from that of my editor. It's Twitter, which he worries is eroding our attention spans, but which I love unequivocally (admittedly, I was never that good at concentrating to start with). One of the reasons that the blog I wrote gathered such attention was that it was shared on the microblogging site by a host of people - journalists, celebrity tweeters, activists. Since then I've heard from women (and men) as far away as Australia and the US.

Twitter, unlike many internet forums, has a culture of using your real identity, and is therefore much more civil than the online badlands. Is it too much to suggest that all internet comments must be made under your real name?

Not eating Bree

There's a fascinating phrase in the Hollywood publicist's lexicon: DIPE, or "documented instances of public eating". It involves getting whippet-thin actresses who normally get by on smelling a celery stick to order cheeseburgers, gallons of Coke and two slices of chocolate cake when they're interviewed by journalists. The resulting article then breathlessly reports this, noting their "naturally fast metabolism".

It stands to reason that not every actress or model can have such miraculous biochemistry, and every so often someone gives the game away. In 2008, Desperate Housewives' Marcia Cross blurted: "Not eating is a constant struggle. It's like they pay me not to eat. It's a living hell." Now, a Victoria's Secret lingerie "Angel", Adriana Lima, has revealed the astounding discipline needed for a career prancing around in skimpies: twice-daily workouts for three weeks before a show and no solids - just protein shakes - for nine days. Lima says that she normally drinks a gallon of water a day, but 12 hours before going on the catwalk, she will stop entirely: "so you dry out, sometimes you can lose up to eight pounds just from that". One fashion editor describes the regime as being like that of a long-distance runner, although I imagine they're allowed to eat solids.

Pizza his mind

Who could fail to be fascinated by Herman Cain, the pizza impresario-turned-Republican presidential front-runner? Allegations of sexual harassment could yet derail him but until now he's been unstoppable in spite of a string of gaffes, including the suggestion the Chinese have "indicated that they're trying to develop nuclear capabilities" (indeed they did, Herman: in the 1960s). My favourite Cain utterance was when he was asked how he would deal with the kind of "gotcha" questions that stumped Sarah Palin. Simple, said Cain: "When they ask me who is the president of Ubeki-beki-beki-beki-stan-stan I'm going to say, you know, I don't know. Do you know?" You can't argue with that. I have a terrifying feeling that the US has found its own Boris Johnson.

Batman and Susan

In between playing Batman: Arkham City on my XBox 360, I note that Susan Greenfield, the baroness, neuroscientist and former head of the Royal Institution, has been talking about video games. Having earlier ascertained, apparently without the need for pesky peer-reviewed research, that Facebook is melting children's brains, she also believes that games could lead players to "lose their identities".

I'd like to give you my thoughts on whether that is likely - and whether it's advisable for scientists to float unsupported ideas from a position of authority - but I'm afraid I've got to save Gotham City from the Joker.

You can follow Helen on Twitter: @helenlewis