This is somewhat interesting:
BRITAIN'S internal security service MI5 sought in 2001 to plant eavesdropping devices inside the walls of a London embassy belonging to one of its main allies, The Sunday Times newspaper in Britain reported.
In a front-page report, the newspaper said that under the Official Secrets Act it could not identify the country targeted, and could only say that it was "one of Britain's allies in the war on terror".
But it said that a former MI5 agent, given the code name Notation, had alerted the embassy to the spying operation.
"For four months from September 2001, MI5 infiltrated the embassy, stole codes used by embassy staff for sending secret messages and planned to plant listening devices and remove documents," The Sunday Times said.
Of course, all that's been released is that the nation at issue is an "ally" in the war on terror. Considering that the British and American governments routinely use that phrase to describe countries that are actually relatively hostile to us, this could be almost anyone. If they're talking about Pakistan or "Saudi" Arabia, then I sure hope they've been trying to bug their embassy.