Via IP, a fascinating Guardian story on "planespotting": How planespotters turned into the scourge of the CIA.

Planespotters make a hobby of tracking airplanes by their takeoffs and landings. Using the connectivity of the Internet, they can now build detailed records of flight patterns -- including deviations from pattern that secretive government agencies would prefer to hide: the "rendition" of terror suspects to secret camps or torture spots.

The recording of flights by spotters like Paul from places as far afield as Bournemouth and Karachi has unintentionally played a significant role in helping journalists and human rights groups expose the scale of the CIA's renditions system. But his impact on such international intrigue largely passes Paul by.

Aggregation and enhanced search capability make public things that were once secret by obscurity. The government uses this to its advantage when it tries to purchase large private databases to datamine for suspicious stand-outs, and now it's feeling the heat on the other side. Why do I suspect we won't reach a David Brin-like entente?