Jacob Snow, a technology and civil liberties attorney for the ACLU, has been making the rounds telling media outlets that a newly publicized patent from Amazon paints a picture of a dystopian, “nightmarish” future. Strong words for a patent application that’s starting to make headlines over fears that Amazon could use the Ring doorbell camera company it acquired to build a robust tool for creepy surveillance.

The patent application envisions using a combination of doorbell cameras and facial recognition technology to build a system that could be used to match images of people who show up at your door to a “suspicious persons” database. The system would even pull up information about that person if it finds a match in the database. Homeowners would also be able to upload photos of people they think are suspicious, which doesn’t sound like it could be misused at all.

When the system gets a hit after searching the database, the details could quickly be sent to the police.

Already, the bare bones of such a system is already in place at Amazon’s Ring subsidiary. Ring CEO Jamie Siminoff told CNET that users are already sharing information about crimes and criminals with other Ring users. “We’re seeing it become a foundation,” he said. They’re sharing that information within an app Ring launched in May called Neighbors, which lets people view details about and comment on crimes and related events in their area.

Naturally, privacy advocates are concerned. Snow told Fox News, regarding the new patent, that “Amazon is dreaming of a dangerous future, with its technology at the center of a massive decentralized surveillance network, running real-time facial recognition on members of the public using cameras installed in people’s doorbells.”

Worth noting is that patent applications aren’t guarantees that a product or technology will ever emerge in the future. Nevertheless, it’s also good to point out that Amazon already landed in hot water earlier this year over its Rekognition facial recognition system that it’s sold and marketed to law enforcement agencies.

That system was criticized, among other things, over being discriminatory toward minorities, and it also made at least one high-profile gaffe. The ACLU showed how it compared photos of congressmen to a database of mugshots and wrongly identified more than two dozen lawmakers as arrestees.

Amazon hasn’t commented over plans related to the doorbell cameras and facial recognition. About the patent application, though, Snow told The Washington Post that “This application gave me chills.”