But as more police agencies join with the company known as Ring, the partnerships are raising privacy concerns. Critics complain that the systems turn neighborhoods into places of constant surveillance and create suspicion that falls heavier on minorities. Police say the cameras can serve as a digital neighborhood watch. Critics also say Ring, a subsidiary of Amazon, appears to be marketing its cameras by stirring up fear of crime at a time when it's decreasing. Amazon's promotional videos show people lurking around homes, and the company recently posted a job opening for a managing news editor to "deliver breaking crime news alerts to our neighbors. ""Amazon is profiting off of fear," said Chris Gilliard, an English professor at Michigan's Macomb Community College and a prominent critic of Ring and other technology that he says can reinforce race barriers. Part of the strategy seems to be selling the cameras "where the fear of crime is more real than the actual existence of crime. "The cameras offer a wide view from wherever they are positioned. Homeowners get phone alerts with streaming video if the doorbell rings or the device's heat sensors detect a person or a passing car. Ring's basic doorbell sells for $99, with recurring charges starting at $3 a month for users who want footage stored. Ring says it stores the recordings for two months.