British MPs have filed suit in a US court to force the CIA to disclose information about British involvement in the extraordinary rendition of terror suspects. From the Age: MPs want to learn more about the use of British airports and air space, about agreements between the US and the UK on rendition, the use of Diego Garcia, a British territory in the Indian Ocean, and about the transfer of detainees from British to American hands.
They have also demanded information about specific detainees, including two rendered through Diego Garcia, and others whom British special forces in Iraq handed over to US forces, and who were then flown to Afghanistan. The report notes that the all party group has been unsuccessful in getting information from the British government. More information about the work of the all-party group can be found here. There is more media coverage at the Guardian. This suit is extraordinary because parliamentarians of one country rarely use a foreign sovereign's legal system to get redress against their own government.
The term 'extraordinary rendition' refers to the secret transfer of people from one country to another against their volition. They are not given due process and are frequently held in legal blackholes for indefinite periods in poor conditions. The Center for Constitutional Rights and other human rights groups have also filed suits in the US to obtain documents about rendition. If successful, this could be a path-breaking case.