If the FBI gets the power to order proprietary software developers to make changes, it will use that to do more than snoop on you. It will take over your digital devices' proprietary software and do to you whatever it wants. The argument about a car directed to bomb the White House is invalid, because that car is no more or less dangerous than one driven by a suicide bomber. I presume the Secret Service has already arranged measures to stop either one. Even if laws stop the FBI from turning all your devices against you, the software's developers could do it. So could rogue employees, blackmailed employees, and crackers that have broken the company's security. There is only one real solution, and that is to shun nonfree software in these devices. You can never trust a nonfree program.