As suspected no UK law enforcement agencies were involved in the Indymedia disk seizure scandal, according to this response to a Parliamentary Question:
Mr. Allan: To ask the Secretary of State for the Home Department which UK law enforcement agencies were involved in the seizure of computer disks containing material published by Indymedia from the London offices of Rackspace. 
Caroline Flint [holding answer 18 October 2004]: I can confirm that no UK law enforcement agencies were involved in the matter referred to in the question posed by the hon. Member for Sheffield, Hallam.
Jeremy Corbyn: To ask the Secretary of State for the Home Department under what powers, and acting under what information, officials of his Department seized web services belonging to Indymedia; and if he will make a statement. 
Caroline Flint: I can confirm that no UK law enforcement agencies were involved in the matter referred to in the question posed by my hon. Friend. In the circumstances I do not therefore believe that it is necessary for me to make a statement. "
The questions about whether or not Rackspace's UK subsidiary have acted illegally under United Kingdom law, by intercepting "electronic communications" (including emails), disrupting an electronic communications system, export of personal data outside of the European Union to the USA without permission, breach of copyright etc. still need to be answered.
Without the protection of a properly authorised UK law enforcement warrant, which was obviously not obtained in this case, Rackspace UK could be sued for breach of confidentiality by the Indymedia systems administrators with whom they have a legal contract.
What this scandal means for web site publishers, bloggers etc. and businesses in general who use shared IT infrastructure facilities owned by foreign companies also remains to be clarified.