James C. Katz is a film historian and preservationist who has restored and reconstructed a number of classic films. Though he began his career as a film producer, he concentrated his attention on preserving existing films... (wikipedia)
Having personally witnessed and fought vigorous efforts by the other side to disenfranchise voters, I'm encouraged by the desire to build long-term infrastructure to protect voting rights.
Many young people have told me how a boyfriend or girlfriend will grab the phone when they are not around and go through the 'Recent Call' list. Or in some cases, pry it from hands and demand they explain who that was.
Every group and every tribe has some method of shunning and throwing people out.
It's technically feasible, both for airplanes and subways. It's the social aspect that's really the most intractable.
Indeed, when people lose their cell phones, it's like losing their minds. And they forget who their friends are because they have lost their cell phones.
In our high-tech era, deleting somebody from your cell phone book is the equivalent of throwing them out and shunning them.