Over 140 major brands are paying for ads that end up on unreliable AI-written sites, likely without their knowledge. Ninety percent of the ads from major brands found on these AI-generated news sites were served by Google, though the company’s own policies prohibit sites from placing Google-served ads on pages that include “spammy automatically generated content.” The practice threatens to hasten the arrival of a glitchy, spammy internet that is overrun by AI-generated content, as well as wasting massive amounts of ad money.

Most companies that advertise online automatically bid on spots to run those ads through a practice called “programmatic advertising.” Algorithms place ads on various websites according to complex calculations that optimize the number of eyeballs an ad might attract from the company’s target audience. As a result, big brands end up paying for ad placements on websites that they may have never heard of before, with little to no human oversight.

To take advantage, content farms have sprung up where low-paid humans churn out low-quality content to attract ad revenue. These types of websites already have a name: “made for advertising” sites. They use tactics such as clickbait, autoplay videos, and pop-up ads to squeeze as much money as possible out of advertisers. In a recent survey, the Association of National Advertisers found that 21% of ad impressions in their sample went to made-for-advertising sites. The group estimated that around $13 billion is wasted globally on these sites each year.