[texec]

It's not too complicated, see starbugs latest talk:

https://media.ccc.de/browse/congress/2014/31c3_-_6450_-_de_-...

(Download MP4 and use a desktop player, it contains an English translation)

[Flockster]

In that talk he even describes, how they got the fingerprint from the German Secretary of Defense from a photograph taken in a distance of 3m at a press conference.