Amazon customers have one week to opt out of a plan that would turn every Echo speaker and Ring security camera in the US into a shared wireless network, as part of the company's plan to fix connection problems for its smart home devices.

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.

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.

"Amazon Sidewalk is a shared network that helps devices work better," the company said in a Q&A document for users. "In the future, Sidewalk will support a range of experiences from using Sidewalk-enabled devices, such as smart security and lighting and diagnostics for appliances and tools."

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.