As easily as Mozilla can make an open-source DRM client... simple (DRM will be broken sooner rather than later, if it hasn't been already), but you can't distribute it. So we're back to "pirate channels", like all the movies today.
And in any case, this misses the point: non-technical users won't distribute pirated content, even if they could rip it. Who are they going to distribute it to? Friends? Whoever wants free movies, can get them easily. But the main advantage of streaming, on-demand-ness, remains in the hands of the big players, who can afford to lease the servers and pay for the bandwidth.
