It is illegal in the United States for federal prisoners to go on the internet. Most prisoners who have been serving long sentences in prison have never been online. Some inmates have managed to go online through illegally smuggled cell phones. But most of them haven’t tried out smartphones, apps, or instant messaging. Facebook, Twitter, and Yelp are vague concepts. The idea that apps can know where you are or remember your information sounds like sci-fi. They hear about these things from friends, television, and magazines, but it’s hard to conceive what they are and how they have transformed the world.