Its completely crazy, off the wall nuts, to suggest that Extraordinary Rendition isn't highly illegal. Why do you think the whole of Europe is up in arms about it? Its the biggest scandal I can remember. At the airport near my home, where these poor guys are shipped through in chains, there has been a permanent 24 hour peace camp since 2002. There have been arrests in Italy. German government people have lost their jobs. There's been EU investigations. Resignations, etc. How could kidnapping be anything but illegal?
Imagine in your own country if, China for example, was 'extraordinarily rendering' US citizens from their homes off the street. The Chinese might pass a chinese law to allow it. It would still be illegal in the US.... al  bin Baloney (Hows my driving?)