Per my very limited knowledge of the net and all things web like I believe that a jpeg or bitmap picture "code" can be edited to include a message. They can use any web site to post a picture that has this code to pass on messages can they not ?
What ever happend to the volunteers from seven seas that were on these web connections long ago ? Have they gone deep cover to elude publicity as they work to counter the terrorists web complex ?
It's called steganography. I hope the NSA is up to the task.