Walmart’s early use of AI in its stores is not just for convenience. The retailer has confirmed Business Insider that it uses camera-based computer vision technology to prevent theft and losses at its checkouts (including self-checkouts) in over 1,000 stores. Simply called “Missed Scan Detection,” the program alerts staff when an item passes a scanner without actually being scanned, giving staff a chance to intervene. Most incidents are unintentional, such as forgetful shoppers or overtired cashiers, but Walmart obviously hopes this will deter thieves hoping to make off with unscanned items.

The chain of stores uses technology from several companies, including Everseen. The technology has been in use for two years.

If you ask the company, it seems to be working. Spokeswoman LeMia Jenkins said BI that shrink rates (the loss of goods due to theft and accidents) have decreased in stores that use computer vision. The question is whether or not the system takes privacy concerns into account. While many stores have security cameras, few use AI to investigate activity at that level. How long does Walmart store the data and is it identifiable? We’ve reached out to Walmart for comment, but it’s safe to say that many customers aren’t aware that AI is in use.