The proposal, called Amazon Sidewalk, involves the company’s devices being used as a springboard to build city-wide “mesh networks” that help simplify the process of setting up new devices, keep them online even if they’re out of range of home wifi, and extend the range of tracking devices such as those made by Tile.

The feature works by creating a low-bandwidth network using smart home devices such as Amazon Echoes and Ring security cameras. At its simplest, it means that a new Echo can set itself up using a neighbour’s wifi, or a security camera can continue to send motion alerts even if its connection to the internet is disrupted, by piggybacking on the connection of another camera across the street. Other devices that don’t need a high-bandwidth connection, such as smart lights, pet locators or smart locks, can use Sidewalk all the time.

But Sidewalk has come under fire for the apparent lack of transparency with which Amazon has rolled out the feature, as well as the limited time available for users to complete the tricky process required to opt out. Other critics have expressed concerns that failing to turn the setting off could leave customers in breach of their internet service provider’s terms and conditions.

But the company’s plans have caused alarm among observers. Ashkan Soltani, a former chief technology officer of the US Federal Trade Commission, told the tech site Ars Technica: “In addition to capturing everyone’s shopping habits (from amazon.com) and their internet activity (as AWS is one of the most dominant web hosting services) … now they are also effectively becoming a global ISP with a flick of a switch, all without even having to lay a single foot of fiber”. The feature may also break the terms and conditions of users’ internet connections, which do not allow such resharing, warned Lydia Leong, an analyst at Gartner.