British Prime Minister Theresa May has responded to last night’s attack in central London in part by calling for tighter controls on online communication. Her words have outraged some technologists who say that the proposal is both unacceptable and at fundamental odds with the spirit of the Internet.
"We cannot allow this ideology the safe space it needs to breed," May said. "Yet that is precisely what the Internet, and the big companies that provide Internet-based services, provide. We need to work with allied democratic governments to reach international agreements that regulate cyberspace to prevent the spread of extremist and terrorism planning. And we need to do everything we can at home to reduce the risks of extremism online."
She added: "We need to deprive the extremists of their safe spaces online."
The comments continue a string of anti-privacy declarations from May’s Conservative government including calls in March for a so-called backdoor to the WhatsApp secure messaging service and major increases in Internet control. May was a sponsor of the Investigatory Powers Act that gave the U.K. government broad surveillance powers.
Get Data Sheet, Fortune’s technology newsletter.
Even as they mourned a tragedy that left several Londoners dead and scores injured, commentators showed little but contempt for May’s perspective.
In a long screed, author and BoingBoing co-editor Cory Doctorow eviscerated May’s comments as a “classic piece of foolish political grandstanding” from a politician who “doesn’t understand technology very well.” Restricting cryptography or building the kind of backdoors that May wants would cripple the Internet as we know it, Doctorow argues: "There's no back door that only lets good guys go through it." Besides, he adds, it can’t even be done from a technical standpoint—the Internet simply isn't built for top-down administration.
"There is no legal or technical mechanism by which code that is designed to be modified by its users can co-exist with a rule that says that code must treat its users as adversaries and seek to prevent them from running prohibited code," he writes.
Zack Beauchamp at Vox points out that May’s desire for a digital lockdown probably couldn’t prevent attacks like the one that happened in London, even if it could be implemented. That’s because, as May herself has made clear, there’s no sign that the attackers were part of a broader terrorist network, or connected to perpetrators of other recent attacks. Crude attacks of this sort, says Beauchamp, generate few digital warning signs.
"It’s hard to catch people who plan their attacks quickly and don’t communicate widely," he writes. "You can’t stop someone from driving their car to a crowded area and ramming pedestrians."
Writing at the Guardian, Charles Arthur says May's proposed Internet regulations "open a Pandora's box" of complication.
"The British government could insist that the identities of people who search for certain terror-related words on Google or YouTube or Facebook be handed over," Arthur writes. "But then what’s to stop the Turkish government, or embassy, demanding the same about Kurdish people searching on 'dangerous' topics?"
The denizens of 4chan, the popular (and often anonymous) Internet message board and community, were less refined but no less forceful in their analysis of May’s position.
Among the reproducible comments from its "Internet Regulation" section: "they dont care about terrorism they want control over population" and a sarcastic "BAN THE INTERNET."
Not everyone agrees. John Mann, Member of Parliament for England's northern Bassetlaw district, offered support for May's position. "I repeat, yet again, my call for the internet companies who terrorists have again used to communicate to be held legally liable for content," he tweeted Sunday morning.
Meanwhile some prominent Brits such as media personality Piers Morgan have tried to draw attention to massive cuts made to British police forces under May and the Conservatives. May’s critics are blaming those cuts, rather than online freedom of speech, for enabling recent attacks—an argument that could seriously weaken May’s anti-terrorism position in advance of a national election on Thursday.