[molticrystal]

Once you are at physical access, you can go to town. Optical surveillance and even recording the sound of the keys being stroked to calibrate[0] an acoustic cryptoanalysis algorithm.[1]

[0] https://www.schneier.com/blog/archives/2005/09/snooping_on_t... [new algorithms require less time]

[1]https://en.wikipedia.org/wiki/Acoustic_cryptanalysis