THE timing was dire. On January 25th American senators reintroduced a bill granting the president emergency powers to shut down parts of the nation's internet as a defence against cyber-attack. Three days later Egypt's embattled autocrats took their country offline.

The American bill's backers never expected an easy victory. But outrage at the five-day shutdown of Egypt's once-flourishing internet (used by 20m people there) and its mobile-phone network (used by 55m) has given opponents of the “kill switch” in America and elsewhere some powerful arguments. The people in charge of the internet in places such as Germany, Austria and Australia were among those who felt obliged to confirm that their governments would not seek similar powers.

Proponents of the American bill countered that they would never want a shutdown on Egyptian lines. Laws that govern radio and television broadcasts already give the American authorities the right to shut bits of the internet, they argue. The new bill merely clarifies and limits such powers. These would be needed, for example, if hackers took control of nuclear facilities, or were about to open the Hoover dam. Critics call this scaremongering and fear that the White House will gain unnecessarily sweeping powers. The people who run the networks are themselves best-placed to keep them safe, they argue.

Either way, in America the size and complexity of the networks, coupled with the fierce protection of laws guaranteeing free speech, make blackout or manipulation on an Egyptian scale almost unthinkable. A remote “kill switch”, even if authorised, would be hugely complex and expensive to build and run, though some worry that the new cybersecurity agencies proposed by lawmakers are just the kind of bodies that would have a go.

The big lesson of Egypt may be less the danger of overmighty government than what it shows about how national authorities can (and can't) close down the internet. The authorities there simply told internet service providers (ISPs) to switch off their computers. The bulk of Egyptian internet surfers use only five providers. In less competitive markets, even fewer need be nobbled. In America, by contrast, the top five ISPs account for only half the market and the top ten for 70%. An American internet shutdown would require the co-operation or coercion of many hundreds of companies and individuals.

Mobile operators are increasingly ISPs too, as phones become smarter. In Egypt the authorities forced joint ventures run by Britain's Vodafone and France Télécom to suspend call and data transmission, citing the laws which govern their licences. Even after the operators were allowed to restore their services, the authorities used them to send propaganda messages. One read: “The Armed Forces asks Egypt's honest and loyal men to confront the traitors and criminals and protect our people and honour and our precious Egypt.”

Egypt's blackout had plenty of chinks. Several groups abroad offered internet access through the terrestrial phone system to Egyptians who could afford to dial in with old-fashioned modems, though the service was slow and the calls expensive. Google and Twitter launched a “speak-to-tweet” service, enabling Egyptians to leave voicemails which were then converted into text and published on Twitter's microblogging service. People dusted off ham radios and fax machines.

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The more complex communications networks become, the harder it is to disable them swiftly, remotely or unilaterally. Cutting the fibre-optic cables that connect a country to the world, for example, might seem easy. The pipes are vulnerable: in 2008 Egypt temporarily lost more than two-thirds of its bandwidth when two submarine cables in the Mediterranean were severed, possibly by ships' anchors.

But crudely disconnecting cables risks outrage elsewhere: much of the internet traffic between Europe and Asia passes through the cables which also serve Egypt, for instance. And cutting international cables leaves a country's internal connections intact: the Egyptian authorities wanted not only to shut their citizens off from the outside world, but also to stop them communicating with each other.

Egypt is not the only country to try to suspend the national internet. In 2007 the authorities in Myanmar cut internet connections to counter anti-government demonstrations. Two years earlier a similar move severed services in Nepal. During the unrest in Tunisia in January, the authorities censored some news and social networking sites; Iran and Thailand have done likewise. Following ethnic riots in its Xinjiang province in 2009, China blocked e-mail, text messages and all but a handful of websites in the region as part of disruption that lasted for ten months; it has lately blocked searches for “Egypt” on several popular microblogging sites. But only North Korea denies its entire civilian population any access to the net.

Such regimes are unlikely to take heart from Egypt's experience. The internet and mobile crackdown did not derail the protests. The Organisation for Economic Co-operation and Development, an intergovernmental think-tank in Paris, estimates that the network shutdowns alone may have cost Egypt as much as $90m.

If anything, one lesson seems to be that enforced closure of the internet can backfire. A much cited slogan of late on the web is “If your government shuts down your internet, it's time to shut down your government.” Some governments are eager to stress their commitment to open web access for all, no matter what. Estonia made internet access a human right in 2000. France has followed suit. A law passed in Finland last year guarantees every citizen a broadband connection.

Yet mandating internet access as a matter of course is far easier than guaranteeing it during national emergencies. And a greater threat for the internet than kill switches—as well as cable cuts and human error, for that matter—is creeping and muddled regulation.