"A developer sells software called StripIt that removes the restrictions on movies purchased from the iTunes Store. Developer is sued. Contributory infringement, or what I’ve been calling Sony-style infringement, might be found here, depending on what other uses the software has. Cautionary note: there was no liability in Sony. So when I say Sony-style liability, I mean liability on the ground discussed in Sony. Sony itself was not found liable under what we’re calling a Sony theory. Contributory infringement is liability for merely placing a product on the market that is not capable substantial noninfringing uses. In other words, if your product is really only good for infringement, you can be liable for the illegal copying of those who use it. Here, StripIt appears to be useful only to remove the protections that prevent unauthorized copying of digital movies purchased from iTunes. We’d want to know, though, whether it’s capable of other uses. Further, we’d want to know how often the product is used to enable users to make fair use copies of movies they have bought. (There is another statute, the controversial DMCA, that governs the intentional circumvention of anti-copying measures.)"