The Economist explains: How does an internet name become an internet address? | The Economist: " . . . the underlying problem remains. DNS can still be poisoned through computer viruses that affect local networks or compromised servers that have their DNS subverted. Beyond poisoning, simpler attacks work too: China's recent outage occurred because of a denial-of-service (DoS) attack against one of its top-level DNS hosts, overloading it with bogus traffic and preventing people from performing DNS lookups. . . ."