"In the present matter regarding Indymedia, Rackspace Managed Hosting, a US based company with offices in London, is acting in compliance with a court order pursuant to a Mutual Legal Assistance Treaty (MLAT), which establishes procedures for countries to assist each other in investigations such as international terrorism, kidnapping and money laundering. Rackspace responded to a Commissioner’s subpoena, duly issued under Title 28, United States Code, Section 1782 in an investigation that did not arise in the United States. Rackspace is acting as a good corporate citizen and is cooperating with international law enforcement authorities. The court prohibits Rackspace from commenting further on this matter.
For additional information on the MLAT, please visit http://library.lp.findlaw.com/articles/file/00297/002460/title/Subject/topic/Criminal%20Justice_Extradition%20and%20Detainers/filename/criminaljustice_2_2251"
This appears to confirm the suspicion that a gagging order has been made. The other point to note is that the company confirm that the investigation "did not arise" in the US.
Liberty confirmed that they have been contacted about the case and are looking into it.