There are reports on Twitter of bombs exploding on the London Underground, the official news media talks blandly of electrical power surges, the mobile phone networks are jammed by people making calls, there is panic, the stock market crashes. But there are no actual bombs. Instead, there is a virtual bomb, an information bomb, detonated by a Twitter terror cell. The blast radius is measured by the mass propagation of uncertainty through information networks. The toxic effects last for 72 hours. And the trigger is an expertly crafted micro-narrative, designed to exploit prevailing social anxieties. Did Orson Welles get there first? See http://www.telegraph.co.uk/culture/tvandradio/10414205/Terror-spread-by-radio-play-Read-the-Telegraphs-1938-report-on-Orson-Welless-War-of-the-Worlds-broadcast.html