Not quite Linux, but interesting (scary?) nonetheless...
"Security researcher Mordechai Guri with the guidance of Prof. Yuval
Elovici from the cyber security labs at Ben-Gurion University in
Israel presented at MALCON 2014 a breakthrough method ("AirHopper")
for leaking data from an isolated computer to a mobile phone without
the presence of a network. In highly secure facilities the assumption
today is that data can not leak outside of an isolated internal
network. It is called air-gap security. AirHopper demonstrates how the
computer display can be used for sending data from the air-gapped
computer to a near by smartphone. The published paper and a
demonstration video are at the link."
-- source: http://it.slashdot.org/story/14/10/31/141207
Peter Reutemann, Dept. of Computer Science, University of Waikato, NZ
Ph. +64 (7) 858-5174