Electronic surveillance

Shops are using spy techniques to monitor customers' facial expressions

Shops are using new spy techniques to monitor customers' facial expressions, heart rate and even pupil dilation while they browse the aisles.

New technology being installed by retailers in Europe and the US, and being trialed in the UK, can spot if a customer cannot find a product, read their reaction to an outfit or spot thieves in a bid to keep up with online retailers.

Technology installed by one French bookseller is able to detect shoppers' movements and facial expressions and alert staff that they may require assistance.