Amazon faces a privacy backlash for its Sidewalk feature, which turns Alexa devices into neighborhood WiFi networks that owners have to opt out of

• Amazon Sidewalk is launching in the US as an opt-out feature that the company says will connect Echo and Ring doorbells to any nearby Alexa device, even those owned by your neighbors.
• Amazon says Sidewalk uses WiFi from neighbors to create "a shared network that helps devices work better," but some have raised privacy concerns.
• Amazon also apologized to Alexa owners outside the US, some of whom were notified of the US-only launch.

Amazon customers are being automatically opted in to Sidewalk, a feature set to launch later this year that the company says will connect Alexa devices to nearby WiFi networks, even those owned by someone else.

Sidewalk uses Alexa devices, including Echo and Ring video doorbells, to create a "shared network" meant to help "devices work better," Amazon said in an email to device owners. It allows nearby devices to use a portion of a neighbor's WiFi bandwidth so devices can have more range.

Amazon said on a launch page: "These Bridge devices share a small portion of your internet bandwidth which is pooled together to provide these services to you and your neighbors. And when more neighbors participate, the network becomes even stronger."

Anticipating privacy concerns, Amazon published a research paper detailing the technology behind Sidewalk and the steps taken to keep users' data private. The company concluded that privacy was one of the "foundational principals" of Sidewalk's design.

"By sharing a small portion of their home network bandwidth, neighbors give a little – but get a lot in return," the report's authors said.

Some were still skeptical of whether such a network would keep user data private. Alan Woodward, a professor at the University of Surrey who specializes in cybersecurity, told BBC News that Sidewalk should be an opt-in feature, adding, "It feels wrong not knowing what your device is connected to."

Ian Thornton-Trump, the chief information security officer at Cyjax, told Forbes the launch was "deeply problematic from a privacy perspective."

"The 'on by default' approach is not consumer-friendly," Thornton-Trump said. "'No one rides on my WiFi for free,' especially a giant corporation with billions of dollars."

In an emailed statement, an Amazon representative confirmed Sidewalk would be automatically enabled for existing customers.

"But well before Sidewalk launches, we will notify existing customers with eligible Bridge devices so they can consider the benefits of Sidewalk before deciding if they want to change their preferences," the representative said. "After all existing customers are notified, all customers setting up a Sidewalk Bridge for the first time will have the opportunity to enable Sidewalk during device setup. All customers will have the option to change their Sidewalk preferences anytime in their Alexa app or Ring Control Center settings."

As of Wednesday, Amazon was rolling out Sidewalk only in the US, but some outside the country on social media reported getting an email about its launch.

Amazon apologized on Twitter via its Support account, saying: "I apologize for any confusion. We recently began emailing customers with Echo devices registered in the US to give them more information about Amazon Sidewalk. This service will only be available in the US when it launches."