On 7 October, the London premises of Rackspace, a Texas-based company that houses and manages web-server computers used by Indymedia - the independent, internet-based global information service - received a surprise visit. A couple of men turned up, seized two web servers and promptly shut down 21 Indymedia sites. Within hours, www.indymedia.org.uk was back online; but at the time of writing, at least a dozen sites were missing large parts of their archives - more than a million text, image and sound files.
Indymedia, which won the New Statesman New Media Award for advocacy in 2002, was founded in the run-up to the World Trade Organisation protests in Seattle in 1999. Since then the network has expanded to more than 140 Indymedias, from Andorra to Uruguay.
Who seized the servers? The first report that Indymedia received, from Rackspace, suggested that the US Federal Bureau of Investigation had shown up with a warrant in London.
Rackspace subsequently sought legal advice and is now prepared only to say that it complied with an order "pursuant to a mutual legal assistance treaty". Meanwhile, the Metropolitan Police maintains that "we were not involved in that particular job". Another UK police spokesperson told me: "We are as mystified as you are as to who did this."
The FBI's Joe Parris told Agence France Presse that it was "not an FBI operation . . . the subpoena was on behalf of a third country". It seems increasingly likely that the third country was Italy - where, as it happens, Indymedia volunteers were brutally beaten by police in Genoa in 2001.
It seems alarmingly possible, as a UK civil liberties campaigner notes, that "The United States has been able to grab a very important media site without explaining what they are doing - and that, of course, is very worrying".
"Someone wants to stifle these independent voices in journalism," Aidan White of the International Federation of Journalists told me: "We need a full investigation into why this action took place, who took part, and who authorised it."