[Cryptography] russian spies using steganography?

[ianG]

http://www.theguardian.com/world/2016/may/07/discovered-our-parents-were-russian-spies-tim-alex-foley?CMP=share_btn_tw

Bezrukov and Vavilova communicated with the SVR using digital 
steganography: they would post images online that contained messages 
hidden in the pixels, encoded using an algorithm written for them by the 
SVR. A message the FBI believes was sent in 2007 to Bezrukov by SVR 
headquarters was decoded as follows: “Got your note and signal. No info 
in our files about E.F., BT, DK, RR. Agree with your proposal to use 
‘Farmer’ to start building network of students in DC. Your relationship 
with ‘Parrot’ looks very promising as a valid source of info from US 
power circles. To start working on him professionally we need all 
available details on his background, current position, habits, contacts, 
opportunities, etc.”