In 2018, Amazon announced a new feature for its Ring doorbells. The system automatically recognizes people, making it easier for homeowners and tenants to see and track everyone coming to their home or apartment.

There are added features, too: In some communities, local police are asking residents to opt in to a program giving law enforcement access to camera footage. Patents filed by researchers at Amazon show a version of the camera technology with a field of view that extends beyond the doorstep, to driveways, streets, narrow passageways between or behind buildings, and virtually anywhere the smart cameras are placed.

Google’s Nest system similarly identifies faces and allows users to input names, and it can be trained to recognize friends, family, and those who consumers don’t want near their homes. Smart cameras automatically detect a face, zoom in, and follow that person as they move around.

Millions of hours of security camera footage are now being uploaded regularly from these devices. Consumers can access it, share and repost it as they want, and give third parties access to footage as well.

To allay privacy concerns, Nest released a firmware upgrade that turns on a light on each camera anytime it’s recording.