While the popularity of such outlets as the iTunes Music Store has given TV networks new revenue streams, legal issues have made it difficult to for them to unleash a torrent of content from old shows. According to a Financial Times article by Joshua Chaffin, standard contracts between the companies and actors, directors, writers, and other talent don't take into account new media outlets.

For example, many TV shows only obtain music rights for one or two airings of an episode, which forces renegotiations with record companies to get the rights for online sales. In fact, as Mr. Chaffin wrote, "sorting through back catalogues of films and TV programmes -- many of them decades old -- has consumed most of the legal community's attention."

Aydin Caginalp, a partner at law firm Alston & Bird, told the reporter: "There are so many of these to clear, and it's not just the US. You're dealing with rights territory by territory. It's a real headache."

The headache could be so large that a dispute over it could lead to strikes by the Screen Actors and Directors Guilds when their current agreements expire next year. The studios would like to see sales through the iTMS and other outlets considered home video revenue, under which they can deduct 80% for shipping and manufacturing costs before disbursing royalties. Of course, the guilds want them to be considered pay-per-view revenue since they're digital sales, which would mean they get royalties on the total dollars.

Mr. Chaffin noted that digital media revenues are still small, and thus the dollar amounts in dispute are also negligible, but "in such a rapidly evolving industry, no one is sure what the business model will look like in five years, and no one wants to lose out."