The program grew out of a desire to address a gap identified after 9/11 ... The program does not involve the NSA examining the phone records of ordinary Americans. Rather, it consolidates these records into a database that the government can query if it has a specific lead - phone records that the companies already retain for business purposes.
The idea of prosthetics is a tool. Most people's cell phones are prosthetics. If you leave your cell phone at home, you feel impacted by not having it. It's an important part of your daily function and what you can do in a day.