The announcement today of Facebook's forthcoming video app for TV set-top boxes should worry incumbent media companies like Disney, Viacom, or any operation that derives lots of revenue from cable TV. Facebook has confirmed that the app will let people watch Facebook videos through their Apple TV or Amazon Fire TV devices, or their Samsung Smart TVs. This is yet another diversion for cord-cutters—courtesy of Silicon Valley—and yet another incentive to ditch cable for those still paying for it. Of course, Facebook videos won't replace your favorite TV shows, but a video app with the distribution power of Facebook behind it is one more formidable product taking up space alongside the video mafia: Netflix, Amazon Prime, Apple iTunes, and Google's YouTube. Who has time for anything else?