Steg

Stego rasterizes the image, then stegs data into the least significant bit (or LSB) of each of the RGB color values.

Another project being worked on is stegging banned religious books from every language and putting them on the web.

It has become an article of faith that bin Laden and his associates routinely communicate through stegged messages posted on pornographic Web sites.

Sounds like nonsense to me - if you're going to pass stegged files there's plenty of anonymous dropfile sites, no need to use CP facilities which are likely to be subject to extra law enforcement, surveillance and site takedowns etc.

[…]the males [geese] (Gander or Steg)