Given the vast numbers of people who are still, reportedly, unacquainted with all aspects of the fast developing world of social media, one or two definitions may be necessary. Twitter, for example, is a popular forum for exchanging 140-character comments about this or that. Polcyb is the society for the policing of cyberspace. Louise Mensch may be the web's most complex, least easily defined manifestation to date, a kind of multi-platform, self-replicating entity of seemingly unlimited reach that combines the latest in artificial intelligence with, some fear, a virus-like tendency to spread, uncontrollably, across every aspect of the media, 24/7, from publishing to print to social media to radio to television. Some fear temporary dementia and memory loss in the more vulnerable along with, in the long term, more lasting damage if internet providers refuse to offer a filter that would allow users to opt in, rather than out, of the ever-growing number of sites where shocking amounts of Mensch are likely to be encountered.

It is already too late of course to repair the damage of last week, in which this virus, which is also known, yet more confusingly, as a chick-lit provider called Bagshawe, could be seen moving steadily across media platforms, morphing – so rapidly that the decisive moment has yet to be identified – from an appearance as a champion of the "great newspaper man" Rupert Murdoch to its latest, perhaps most brilliant and far-reaching incarnation yet, as a victimised feminist.

Former opponents instantly rushed to her support. Unsympathetic opponents found themselves tagged as sexist fellow travellers. Progressives turned on progressives for calling other progressives names. While Ms Mensch monitored the confusion of issues on Twitter, where she had posted an array of the sexist abuse that followed an appearance on Newsnight, participants in this debate struggled vainly to remove her from a discussion that was really, they insisted, the same one that has been going on for ages, about the horrifying levels of online misogyny.

Why is this environment so much worse for women? Is the sexist language significantly worse than hate speech about disability, race or sexual orientation? Is any of it bad enough to justify formal controls, beyond the existing legislation on hate speech and threatening behaviour?

Infuriatingly, for anyone trying to resist the spread of Mensch, her particular experience of sexism must, unlike her personal style or political attitudes, be pertinent. It does not matter that she once called Ed Miliband "Mr Potato Head". Or that she records for public viewing the online world's prettier compliments on her appearance. Or that she is loyal to Mr "Calm Down, Dear". It is poignant, rather than relevant to the debate, that she is an admirer of Mr Murdoch, whose Sun newspaper has been defending its objectification of women for more than 30 years: "'Fat, jealous' Clare brands Page 3 porn". Joy shall be in heaven over one sinner that repenteth, etc.

But if her Twitter experience can, as some think, be adduced as a further argument for controlling or censoring that medium, it is worth establishing that it amounted, as reported, to an onslaught of depraved, online misogyny that cries out to heaven for corrective action.

In contrast with the mobs that have in the past turned Twitter into an online pillory, using acts of collective bullying as punishments for, say, being rude about a cherished celebrity, the network does not on this occasion appear to have organised a Nineteen Eighty-Four-style hate.

Unlike anonymous, under-the-line commenters on the websites of media outlets who hope, like flashers, to give the women tasked with reading them an ugly, sex-related shock, most of the obscene remarks were not addressed directly to Mensch. Unlike Harriet Harman and Mary Beard, she had not been singled out for sexist denigration by middle-aged newspaper columnists. On the contrary – and this may not mean much to the massive, non-tweeting majority – in order to find the random, horrible remarks about her, the busy Mensch needed actively to search for comments she might never have read at all. Thus she made the interesting discovery – well done, Newsnight – that the programme appears to have conquered the longed-for 16-24 demographic. Or at least a demographic that tweets as if it was between 16 and 24. Without Mensch's search, we would not know there are people exclaiming: "Oh my dayz" at Jeremy Paxman and a tweet such as: "Louise Mensch is such a knob, fuck off slut" would never have found an audience beyond the few score of her followers who already enjoy similar assessments of, say, Tulisa ("Tulisa is an ugly slutty chav") or Justin Bieber ("I hate Justin Bieber so much, stupid twat").

Maybe it is no excuse that a person, Twitter-yakking his or her way through Newsnight, might not think, as he/she shared the unworthy, late-night apercu: "God X is a wanker/cow/knobhead/smug bastard/slag/tosser", or: "I could happily strangle Y", of the consequences if these passing jibes were seen by their target or ended up being deployed, as in this unforgivable case, as a protective device for a champion of Rupert Murdoch. But as Twitter-defenders have pointed out, following CPS action on racist remarks and terrorism gags, this policeable medium is treated carelessly by millions of easily identified users as a safe, semi-private repository for uncensored stream of consciousness. Further evidence that some participants tweet, as they believe in confidence, in the regrettable style of chatty Sky Sports presenters, is not necessarily evidence – as Mensch and some of her supporters would have it – of enough targeted obscenity to deter many women from speaking up. In fact, some might find Twitter, with all its faults, a more congenial venue for ambitious women than Cameron's cabinet or its sister nuthouse, the Daily Mail.

Granted the special insights that come from being a contributor to our own website, it's not even clear to me that the popularity of sex-related insults should be distinguished from all the other forms of aggression, scurrility and assorted hate speech that regularly afflict any forum that does not demand personal identification, payment or both. There may be worse things, even, than unattributable jeers about deformation and unshaggability. Long before the member for Corby pleaded for mercy, women and progressives were demonstrating that not all online malevolence is ignorably knuckleheaded or right wing or potentially covered by the Communications Act. Remember the nicely spoken mummies against Madeleine McCann's parents and their upsetting advertisement, explaining why the whole thing was all their fault?

Last Sunday, while Mensch was presumably on charge, a group of contributors to our website gave up their time to show the family of the late Philip Gould how little they cared about his dying of cancer. Going out of your way to hurt the miserably bereaved: this mystifying lurch into Facebook troll territory seems, unlike the latest yodelling from Louise Mensch, the Sun's current "hero of the week", a really pressing reason to address the cruelty that sloshes anonymously around the internet.