It seems inevitable that second thoughts would arise about the privacy tradeoff of using an Internet-connected camera for home security or convenience. Concern spread after newscast videos showed people startled by pranksters' voices on their Amazon Ring or Google Next speakers. Unseen hackers teased or harassed victims, including an 8-year-old Mississippi youngster in her bedroom. The intrusions led Ring recently to improve account security and give more privacy control. Two-factor authentication (a double log-in) became mandatory, with no opt-out choice – a step Nest took earlier. Users get a six-digit code via email or text to confirm each sign-in request.

Potential risks also involve the devices' phone apps, such as one that records and saves sound and video from selected locations in a home, garden or patio. That's a way to monitor kids, pets, housekeepers, babysitters and other guests. But a hacker with access also can overhear conversations and watch people. Although that activates a small blue light on the device, users may not notice the spying. An app also displays a user-selected address for the camera, so the live feed could show whether the person is home -- useful for a burglar to know.

A separate issue involves Ring's popular Peephole Cam, which has a doorbell button that sends a phone alert when pressed, plus a small speaker that works as an intercom. Users also get an alert when the camera senses activity, letting them see what's moving outside the door – a way to see mail or package deliveries, visitors or unknown people even when away from home. The camera records 30 seconds of video when it senses motion.

Millions of the devices are in use nationwide, creating a vast source of potential street evidence for police. Some cities offer rebate and voucher programs for the cameras in hopes that more surveillance footage will make crimes easier to solve. Ring lets detectives use a tool to ask customers for videos captured in and around their houses. The number of police forces with access has more than doubled since September to nearly 900 agencies across 44 states, The Washington Post found. Legal experts and privacy advocates voice alarm about threats to civil liberties by turning neighbors into informants, in effect. Ring has found "a clever workaround for the development of a wholly new surveillance network, without the kind of scrutiny that would happen if it was coming from the police or government," said Andrew Guthrie Ferguson, a law professor in Washington, D.C.

Ring says: "Ring believes when communities and local police work together, safer neighborhoods can become a reality." -- Yassi Shahmiri, company spokeswoman

Critic says: "Ring should be shut down immediately and not brought back. The privacy issues are not fixable with regulation, and there is no balance that can be struck. They are simply not compatible with a free society." – Max Eliaser, Amazon engineer

Journalist says: "I spent a couple weeks using an Amazon Ring doorbell camera. I didn't like how it made me feel about my neighborhood, or how i thought it might make my neighbors feel about me." – Max Read, New York magazine writer and editor