[cd34]

Its been done for a long time both with pictures and videos. As to the usefulness, well, the sponsors that I know that have done it use it to track down the accounts that have reposted their videos on file sharing sites and have closed/blocked the trader and the cc# used to join. I know one sponsor mentioned sharing that information with other sponsor sites, but, I don't know whether they did or not.

Steganography isn't new for doing this - and ages ago, someone actually did write a program to strip out stego'ed images from a particular sponsor. Videos do require a bit more horsepower, but, if you really want to protect your work somehow, you have a choice to make.

I know one client that files 50-100 DMCA requests a week against hosts that either host content or link to copyrighted content. There are hosts that ignore them for various reasons and I would say they have less than a 50% success rate at getting their content removed. One filesharing board actually says they will legally pursue anyone that posts their content. I guess that means that if someone posts the same content they have stolen, they have some legal right to it. The logic behind this confuses me.

Stegonagraphy isn't difficult, its not new, its been done many times before, but, it faces the same challenge that DRM had. When Apple first introduced Itunes, the content was stored raw on Akamai's servers, the Itunes client actually did the DRM. This moved the CPU muscle to the client's machine rather than Apple's machines. When this was discovered, Apple changed their system to DRM encode the material at the server side, which required a lot more hardware on Apple's part (and eliminated their ability to use Akamai's edge cache)

Useful, possibly. Practical for images, yes. Practical for videos, questionable.