Via BoingBoing, across the wires the electric message comes that some random geek surfing Usenet has discovered what appears to be a 30 minute news bulletin on a major terrorist assault on the US, with plague, chemicals and crashing jets. All the stuff Mahmoud Abu Rideh would be getting up to, if he wasn't confined to his house during the hours of darkness only.
Reading the description, it seems that the video (which BitTorrent users can obtain here) was prepared as part of the TOPOFF3 (in the US) or ATLANTIC BLUE (in the UK) joint antiterrorist exercise carried out a few weeks ago. The scenario, at any rate, is identical.
This reminded me of the spectacular media fart committed a few years back by Sky News when they falsely reported the death of a Royal (I forget which). As I recall, an Australian working in the Osterley Park spaceship that holds Sky's network centre accidentally encountered a practice run of the prepared broadcast and immediately called home. Either they, or the person they spoke to, then contacted an Aussie radio station, which ran with the story. The thing then went non-linear and spread like wildfire across the world media, until the rebuttals got it.
Strangely, it was difficult to trace the story on the net, until I found a reffo on the Guardian's website. It was the Queen Mother, and it occurred in August, 1993: just before the web, really.