If you encrypt the data (to make it look random) and use a low bit rate you're just adding random looking noise to the stream. It's not possible to find the data. Really not traceable, done right, even if the NSA are running a statistical analysis over their giant stash of data - which I would be if I were them. Assume you're using a truly random one time pad to generate the stenography and I'm pretty sure they'd be screwed. Just remember to generate your content on your secure, air gapped work station, preferable enforcing things like MAC and BLP.