People read a book, they see a simple description of steganography, they whip up an implementation as a proof of concept, they share that code, other people think it's secure when it's not meant to be.

(http://www.ifp.illinois.edu/~ywang11/paper/CISS04_204.pdf)

(http://eprint.iacr.org/2005/305)

(http://vision.ece.ucsb.edu/publications/sullivan_ICIP06.pdf)