> On the one hand the technique has been available for decades, and UMich's Citi group did an interesting project to see if people could both exchange messages

> On the one hand the technique has been available for decades, and UMich's Citi group did an interesting project to see if people could both exchange messages on Ebay using pictures of things for sale, and if so did any images on Ebay have steganographic content (at the time it was the largest source of user supplied images). They didn't find any (except for their own test images). But it presumably continues to be a channel people check. Wouldn't encrypting the data to be hidden, and then hiding it within random data (say, the low bits of image bytes) be perfectly indetectable? I'm assuming that the low bits of image bytes are uniformly random, but even if they're not then one could still hide data in them, it's just trickier.