The other day, I linked to an article not unlike this one that said that the TiVo people are selling, or are about to start selling, data about the viewing patterns of TiVo users. My initial reaction was negative but on reflection, I don't think it's that big a deal. The information at issue is only identified by zip code, meaning that someone will find out that some guy in the 90036 area watched Leno and Conan O'Brien tonight, then skipped through Letterman and watched the late night block on the Game Show Network. That's not much of an invasion of privacy, so I withdraw any concerns I may have implied.
If even that much prying into what you watch bothers you, you can opt out by calling TiVo Central at (877) 367-8486. But I can't imagine that anyone would care that much.