A District Court in Colorado has ruled against "Clean Flicks" and related services which take Hollywood movies, edit out the "sex, nudity, profanity and gory violence," and then sell the cleaned up versions. The court held, on summary judgment, that this is not a fair use. And, because copies of the altered film are sold, the "first sale doctrine" (which says that once you buy a copy of a work, you can do pretty much as you'd like with it) also did not apply. You can access the decision here.
But what if copies weren't made? What if there were a way to "redact" or "bleep" out the objectionable content on the very DVD you (lawfully) purchased, and you then sold that redacted version? Tim Lee suggests that would be fine: "No one would claim copyright infringement if I went into business buying books, blacking out naughty words, and reselling the edited books. [If] Clean Flicks has already paid Hollywood full price for each copy of the movies it re-sells—what business is it of Hollywood’s if they alter the copy before selling it?" One objection to this view might be that the edited book or film is an unauthorized "derivative work." The Clean Flicks court rejected that claim, holding simply that "because the infringing copies of these movies are not used in a transformative manner, they are not derivative works and [therefore] do not violate sec. 106(2)." I'm not convinced that it's so clear a G-rated version of an R-rated movie is not a derivative work, no matter how it's created; at the very least it's a closer call than this decision lets on.
UPDATE: Ed Felten has more thoughts here. He too finds the Court's derivative work reasoning "odd."