The Twitter abuse debate has moved on significantly, onto the question of what the police are doing, and what difference that can make.
The police reacted swiftly, to try to relinquish responsibility, for instance:
Andy Trotter, who leads on social media for Britain's police forces, told the Guardian he feared that "a whole new tranche" of web-based hate crimes could "cause great difficulty for a hard-pressed police service" trying to deal with what could amount to thousands of allegations.
"We want social media companies to take steps to stop this happening. It's on their platforms this is occurring. They must accept responsibility for what's happening on their platforms ...
"They can't just set it up and walk away. We don't want to be in this arena. They are ingenious people, it can't be beyond their wit to stop these crimes, particularly those particularly serious allegations we have heard of over the weekend."
What exactly do we have police for, then, if not to investigate specific, repeated and documented crimes? Giving up on policing Twitter is no more defensible than abandoning a town like, say, Walthamstow to the criminal elements.
For a senior policeman, Mr Trotter also seems sadly ignorant of the law. Even leaving aside the issue of threat of rape as a common law crime, which might involve some difficult issues of sufficiently proving intention (though not many), the Protection Against Harassment Act 1997, especially s 4(1) makes it very clear that two attempts to "cause another to fear that violence will be used against him [sic] " form a course of conduct which is a crime. In the Perez and Creasy cases there are apparently hundreds of such threatening tweets, many retweeted or screencapped.
It is impossible to understand how police who went ahead with investigating cases which involved poorly framed jokes on Twitter can now say they do not have the money to take on genuine, vicious and entirely humorless threats of rape. It seems much more likely that they fear they do not have the technical ability to understand how to police the Net , or the resources, and are terrified, and also worried that having destroyed their credibility on the Net once (see below), things can only get worse. But in that case the remedy is to acquire expertise, not to retreat to a pre 1996 position of declaring the social Internet terra incognita where elephantine trolls roam.
As Lilian implies, asking the police to investigate these crimes may not always inspire confidence among people who are regular users of Twitter. You may be reminded of the heavy handed tactics they employed against Paul Chambers after his joke, or the prosecutions of other people for suggesting that British soldiers deserve to die for their crimes in Afghanistan.
These prosecutions took place using Section 127 of the Communications Act, which criminalises "grossly offensive" speech using a public communications network. It covers a very wide range of potential speech, and it is unclear why the offence exists. In any case, its abuse has led to the Crown Prosecution Service advising that a "high threshold" should be employed in relation to use of S127, because of the free expression impacts. In their advice they note that human rights courts do not hold that mere offensiveness should result in criminalisation of speech. Offensiveness may be necessary to challenge ideas, after all.
The CPS says that communications that are either "credible threats" or "which specifically target an individual or individuals and which may constitute harassment or stalking within the meaning of the Protection from Harassment Act 1997" "should be prosecuted robustly".
Thus the CPS seems to believe that the police should be playing their part by investigating behaviour which would clearly be illegal. This is different from non-credible threats, and activity which does not constitute harassment.
To balance their calls for strong action on illegal activity, Stella Creasy and Yvette Cooper should callfor Parliament to repeal Section 127 so that matters of offensive but non-threatening, non-harassing speech remain clearly out of scope.