Stepping out in public used to make a person largely anonymous. Unless you met someone you knew, nobody would know your identity. Cheap and widely available face recognition software means that's no longer true in some parts of the world. Police in China run face algorithms on public security cameras in real time, providing notifications whenever a person of interest walks by. China provides an extreme example of the possibilities stemming from recent improvements in face recognition technology.

Microsoft and IBM sent congratulatory public messages to president-elect Joe Biden this month. Both expressed hope that his administration would ease the nation's political divisions, and suggested it consider crafting the first federal rules governing face recognition. "When it comes to issues such as safeguards for facial recognition, we have no national law at all," Microsoft president Brad Smith wrote. "We need new laws fit for the future." IBM CEO Arvind Krishna told Biden his company was "ready to work with you" on prohibiting use of the technology for "mass surveillance, racial profiling, or violations of basic human rights and freedoms."