There's one worrying aspect of Tweeters' abuse of high-profile women that hasn't had the attention it should get - that it further undermines what we might call the liberal optimists' case for free speech.
I'm referring to the idea that free speech will enable us to progress towards the "truth". "Wrong opinions and practices gradually yield to fact and argument: but facts and arguments, to produce any effect on the mind, must be brought before it" wrote Mill. Free speech, wrote Rawls, "is necessary if political affairs are to be conducted in a rational fashion."
Such a view seems fanciful. This is not just because free speech gives us rape and bomb threats from those trying to silence women. The free press delivers not so much a healthy diversity of views but a mix of managerialist centrism, imbecilic linkbait and herp and derp. Not that the fault is all on the sell-side. Readers seek out whatever tosh corrobates their prejudice and self-regard, and even when they do encounter balanced reporting, they apply asymmetric Bayesianism and so entrench (pdf) their prejudice.
The idea that free speech will give us intellectual progress seems, then, optimistic. Rawls might be right - it might be necessary for rational debate. But it sure ain't sufficient.
You might object here that freedom has given us social progress; attitudes to women, ethnic minorities and gays are much better now than they were in the 50s and 60s. But I'm not sure this represents a victory for free speech rather than the dying out of old attitudes and the replacement by newer ones; to paraphrase Max Planck, civilization advances one funeral at a time. Indeed, it might even represent the opposite of freedom - a triumph of a new form of conformism which (partially) represses racism, homophobia and misogyny.
However, just because the optimistic liberal case for free speech is weak, it does not follow at all that there's a case for restricting such speech. The pessimistic case for freedom remains.
By this, I mean the idea that it's impossible in practice to cut out sick speech whilst not repressing healthy forms - and as my Top Blogging sidebar shows, there are plenty of these. Several people have rightly pointed out that a "report abuse" button on Twitter will soon become a "report opinions I don't like" button. And this principle generalizes. Powers to restrict egregiously abusive speech will be used to restrict others' freedom. I’d give the Devil benefit of law, for my own safety’s sake.
But then, as a privileged white man, I would say that, wouldn't I?