Retail giant Walmart has recently patented technology that would enable the retail giant to deploy audio surveillance on employees. The stated goal: measuring performance in their stores.

“Tracking performance metrics for employees to ensure that the employees are performing their jobs efficiently and correctly can aid in achieving these costs savings and increases in guest satisfaction,” the patent indicates.

Among the proposed and tentative uses for the surveillance is for measuring how rapidly a cashier can check out customers online, how quickly they bag groceries, and even their interactions with customers.

While Walmart has yet to develop or implement the technology outlined in its patent, privacy and worker’s advocates are concerned. In an interview with Buzzfeed, Cornell Industrial and Labor Relations School assistant professor Ifeoma Ajunwa said:

“The sound recording is helpful for determining if the line is too long, let’s automatically open a new cashier. But then there’s potential for mission creep where it’s more like, ‘as a cashier you’re too friendly, you’re talking too much, and therefore not moving people along, so let’s penalize you.’ Even though the technology is presented as interested in one thing, the fact that it has the potential for both things to be captured is of concern. There’s a lot of potential for misuse.”

Brick-and-mortar retailers are increasingly feeling under threat from and other online businesses. Initiatives such as Walmart’s to increase efficiency and lower overall expenses in their stores are likely to become more common in the near future.