As Black Lives Matter protests continue around the country, police are using facial recognition and all kinds of other technology to arrest protesters and organizers. While, in some cases, the people arrested did commit crimes, after-the-fact arrests can have a chilling effect on free speech and lead to cases of mistaken identity. They also show us just how much surveillance is part of our lives. Molly speaks with Simone Browne, author of “Dark Matters: On the Surveillance of Blackness.”