As grocery shoppers work to digest Amazon's massive acquisition of Whole Foods for $13.7 billion, the digital storefront recently scored a victory that aims to reinforce the company's growing investments in brick-and-mortar retail. Amazon was awarded a patent May 30 that could help it choke off a common issue faced by many physical stores: Customers' use of smartphones to compare prices even as they walk around a shop. But Amazon now has the technology to prevent that type of behavior when customers enter any of its physical stores and log onto the WiFi networks there. Titled "Physical Store Online Shopping Control," Amazon's patent describes a system that can identify a customer's Internet traffic and sense when the smartphone user is trying to access a competitor's website. When that happens, Amazon may take one of several actions. It may block access to the competitor's site, preventing customers from viewing comparable products from rivals. It might redirect the customer to Amazon's own site or to other, Amazon-approved sites. It might notify an Amazon salesperson to approach the customer. Or it might send the customer's smartphone a text message, coupon or other information designed to lure the person back into Amazon's orbit.