We help our clients to manage and publish their media online - images, video, audio, whatever. They always ask my boss whether they can stop users from copying their media, and he asks me, and I always tell him the same thing: no. If the users can view the media, then a sufficiently determined user will always be able to make a copy. But am I right?

I've been asked again today, and I promised my boss I'd ask about it online. So - is there a DRM scheme that will work? One that will stop users making copies without stopping legitimate viewing of the media?

And if there isn't, how do I convince my boss?