Over 600 police forces throughout the US have formed partnerships with the company, which says its technology can be a critical tool in tackling crimes such as trespassing and burglary. Following media reports about these partnerships, Senator Edward J Markey wrote to Amazon -- which owns Ring -- requesting details on the way footage is used, and the steps being taken to protect civil liberties.

Amazon's vice president of public policy, Brian Huseman, responded, noting that the company placed few restrictions on how police use or share the videos. However, he was careful to clarify that homeowners are not obligated to share their footage with authorities, and that Ring does not identify users that refuse police requests for video.

Nonetheless, Markey said in a statement that Ring is failing to enact basic safeguards to protect Americans' privacy. "Connected doorbells are well on their way to becoming a mainstay of American households, and the lack of privacy and civil rights protections for innocent residents is nothing short of chilling," he said.

"If you're an adult walking your dog or a child playing on the sidewalk, you shouldn't have to worry that Ring's products are amassing footage of you and that law enforcement may hold that footage indefinitely or share that footage with any third parties."

In his responses, Huseman did not explicitly rule out the potential for facial recognition technology within Ring's ecosystem. He wrote that it was a "contemplated" feature that would only be released with "thoughtful design," adding that any such product from Ring would be the result of customer demand.