The partnerships let police automatically request the video recorded by homeowners’ cameras within a specific time and area, helping officers see footage from the company’s millions of Internet-connected cameras installed nationwide, the company said. Officers don’t receive ongoing or live-video access, and homeowners can decline the requests, which are sent via emails that thank them for “making your neighborhood a safer place.”…

Ring officials and law-enforcement partners portray the vast camera network as an irrepressible shield for American neighborhoods, saying it can assist police investigators and protect homes from criminals, intruders and thieves.

“The mission has always been making the neighborhood safer,” said Eric Kuhn, the general manager of Neighbors, Ring’s crime-focused companion app. “We’ve had a lot of success in terms of deterring crime and solving crimes that would otherwise not be solved as quickly.”

But legal experts and privacy advocates have voiced alarm over the company’s eyes-everywhere ambitions and increasingly close relationship with police, saying the program could threaten civil liberties, turn residents into informants and subject innocent people, including those who Ring users have flagged as “suspicious,” to greater surveillance and potential risk.