Popular Science article on making your own Tivo with linux raises all kinds of issues:
“For now, whatever you do with your Linux recorder, with the exception of rebroadcasting or selling digitized shows, is still mostly legal. That may change (in the United States at least) if entertainment industry lobbyists get their way: On tap in the current Congress, for example, is one bill that would require any digital device capable of storing copyrighted material to abide by whatever restrictions publishers decide to impose on how the material can be viewed, played, or copied. Another would permit registered copyright owners to hack into any computer they believe might be involved in illicit reproduction of their property, to prevent that computer from sharing the owners’ copyrighted material.”