Amazon has been granted a patent designed to stop you from visiting a shop to buy something, but then looking for a cheaper version online while you're there.
The patent, which we first saw via The Verge, would essentially try and intercept you if you made a price comparison search using the shop's WiFi. It outlines a way that a retailer could intercept and analyse a network request, like a search term or URL.
If the retailer works out that you're probably looking at a competitor's site, it can try and persuade you back with a store coupon, show you that the item's immediately available in-store, or offer a discounted version of the item.
Retailers call this trend of looking at a product in-person and buying it online "showrooming", and it's something that's been worrying them for a while.
As Amazon puts it in its patent: "[A] negative scenario may exist for a physical store retailer when a consumer evaluates items at the physical store, leverages physical store sales representatives, and then reviews pricing information online in order to purchase the same item from an online retailer.
"The physical store retailer pays for floor space, sales representative time, product inventory management, and other costs while not being able to complete a sales transaction."
On the face of it, this anti-showrooming patent looks like a strange move from Amazon, given it's the main beneficiary of this trend.
And Amazon also doesn't have that many physical shops itself — so why would it worry about price comparisons with competitors?
It's instead more likely that the patent is a defensive move against retailers. Now, retailers can't take measures to stop you from logging into their WiFi and looking for their products more cheaply online on Amazon.