The big picture: Ring has revealed how many partnerships it has already built with law enforcement agencies in the US. The arrangements are equally beneficial for both the police, who can now have access to a growing surveillance network that is self-maintained by its users, and Ring who gets some free advertising as a result.

Earlier this month, news broke that Amazon was aiding police in gaining access to Ring doorbell camera footage for use in their investigations. Many privacy advocates criticized the move, but the company defended its practices by explaining that it only shares the video content after receiving a valid and binding legal demand from authorities. The police argued that users know what they're getting into and that this isn't a violation of Fourth Amendment rights.

Now we know from Ring itself that it has already built video-sharing partnerships with more than 400 police forces across the country. The Amazon-owned doorbell camera company calls this the "new neighborhood watch," but an expert told the Washington Post that a more fitting description would be "a clever workaround for the development of a wholly new surveillance network."

Technically speaking, the partnerships let the police make specific requests for Ring to hand over video recorded by homeowners' cameras in a given time frame and area whenever they need help in their investigations. They don't get access to live video, and users are notified every time new enforcement agencies sign up to join the Neighbors Portal through the dedicated app. Owners of the Ring cameras can also report crimes and law enforcement can engage with communities by providing a stream of information about crime and safety events.

The ACLU took to Twitter to express its views on the development, saying that "Amazon’s Ring has created a massive face recognition surveillance network, easily accessible to hundreds of police departments. Big Brother is watching - right at our front doors."

It's worth noting that users can deny the requests and opt out of receiving them by mail or in the Neighbors app. As always, such services could invite abuse that would affect innocent people, but Ring says it was careful in crafting the Neighbors program so that "users always stay in control of the information they share and that their privacy is protected."