a) I meant an app that that would be able to read, for instance, a hidden QR code that's concealed steganographically in, for instance, an innocent looking image of a lolcat. What if, to help people living in censored environments get information from the outside world, you made an app that would be able to read certain class of information codes hidden in images. The police would have trouble scanning every single postcard that enters a country, and you couldn't exactly get someone in trouble for possessing a postcard that has a hidden image in it if they claim not to know about claim (well, if the justice system works at all in such countries). This is just a completely out their brainstorm, but it kind of a cool thought.