FOR a small, high-tech country such as Estonia, the internet is vital. But for the past two weeks Estonia's state websites (and some private ones) have been hit by “denial of service” attacks, in which a target site is bombarded with so many bogus requests for information that it crashes.

AFP

Tallinn's unknown soldier, still embattled

The internet warfare broke out on April 27th, amid a furious row between Estonia and Russia over the removal of a Soviet war monument from the centre of the capital, Tallinn, to a military cemetery (pictured below). The move sparked rioting and looting by several thousand protesters from Estonia's large population of ethnic Russians, who tend to see the statue as a cherished memorial to wartime sacrifice. Estonians mostly see it rather as a symbol of a hated foreign occupation.

The unrest, Estonia says, was orchestrated by Russia, which termed the relocation “blasphemy” and called for the government's resignation. In Moscow, a Kremlin-run youth movement sealed off and attacked Estonia's embassy, prompting protests from America, NATO and the European Union. Perhaps taken aback by the belated but firm Western support for Estonia, Russia has backpedalled. Following a deal brokered by Germany, Estonia's ambassador left for a “holiday” and the blockade ended as abruptly as it began.

But the internet attacks have continued. Some have involved defacing Estonian websites, replacing the pages with Russian propaganda or bogus apologies. Most have concentrated on shutting them down. The attacks are intensifying. The number on May 9th—the day when Russia and its allies commemorate Hitler's defeat in Europe—was the biggest yet, says Hillar Aarelaid, who runs Estonia's cyber-warfare defences. At least six sites were all but inaccessible, including those of the foreign and justice ministries. Such stunts happen at the murkier end of internet commerce: for instance, to extort money from an online casino. But no country has experienced anything on this scale.

The alarm is sounding well beyond Estonia. NATO has been paying special attention. “If a member state's communications centre is attacked with a missile, you call it an act of war. So what do you call it if the same installation is disabled with a cyber-attack?” asks a senior official in Brussels. Estonia's defence ministry goes further: a spokesman compares the attacks to those launched against America on September 11th 2001. Two of NATO's top specialists in internet warfare, plus an American colleague, have hurried to Tallinn to observe the onslaught. But international law is of little help, complains Rein Lang, Estonia's justice minister.

The crudest attacks come with the culprit's electronic fingerprints. The Estonians say that some of the earliest salvoes came from computers linked to the Russian government. But most of them come from many thousands of ordinary computers, all over the world. Some of these are run by private citizens angry with Estonia. Anonymously posted instructions on how to launch denial-of-service attacks have been sprouting on Russian-language internet sites. Many others come from “botnets”—chains of computers that have been hijacked by viruses to take part in such raids without their owners knowing. Such botnets can be created, or simply rented from cyber-criminals.

To remain open to local users, Estonia has had to cut access to its sites from abroad. That is potentially more damaging to the country's economy than the limited Russian sanctions announced so far, such as cutting passenger rail services between Tallinn and St Petersburg. It certainly hampers Estonia's efforts to counter Russian propaganda that portrays the country as a fascist hellhole. “We are back to the stone age, telling the world what is going on with phone and fax,” says an Estonian internet expert. Mikko Hyppönen of F-Secure, a Finnish internet security company that has been monitoring the attacks, says the best defence is to have strong networks of servers in many countries. That is not yet NATO's job. But it may be soon.