[tobehonest]

Plane watches already do this. They have even outed CIA operations.

I wonder how the Government would like it if many hobbyists sat in front of the NSA car park and started writing down every license plate and put them on a searchable database.

Now this is a project I would fund. Kickstarter anyone?

[midas007]

Interesting. Got a reference to that CIA incident?

[markvdb]

There's quite a pile of information on CIA rendition flights. They seem to have used EU member states air space [1][2].

The Washington Post suggests there was at least some journalistic field work plane spotting in the US [3].

[1] http://www.theguardian.com/world/2007/jan/23/usa.eu

[2] http://www.europarl.europa.eu/news/en/news-room/content/2012...

[3] http://www.washingtonpost.com/world/national-security/ten-ye...

[dispense]

There was an entertaining lecture about it this (and other stuff) at the 30C3: http://media.ccc.de/browse/congress/2013/30C3_-_5604_-_en_-_...

[dalke]

Google "plane watching CIA". Second hit: http://www.theguardian.com/uk/2005/dec/10/usa.terrorism1 : How planespotters turned into the scourge of the CIA