In the old days there were places on USENET where you could post anonymously messages that you had encrypted to someone's public key. Then you saved all the posts as a txt file and decrypted all of it against your private key. Anything that decrypted sensibly was for you. Anything else you didn't want to know anyway. Because everyone was always taking everything and because of the very nature of USENETand because of the encryption. It was nearly impossible to establish a record of communication taking place let alone the contents of the communication.

apparently bin laden's crew has been encrypting their communications and then stegging them into porn. Then they use some sort of free picpost to put it up. Can you imagine the feds having to track every visitor to the free pornsites?
And this is the really brilliant part: bin laden now has a leqitimate excuse to hire photographers and models, view porn, and other things that would be frowned upon by nutjob religious extremists like the Taliban, or AG Ashcroft.