X, the company formerly known as Twitter, has been caught running unlabeled ads in users’ Following feeds, TechCrunch has learned and was able to confirm firsthand. While scrolling the Following feed on a Mac using the Chrome web browser, we encountered a handful of unlabeled ads amid other posts from people we follow, as well as other ads that did properly display the “Ad” label at the top right of the post.

Because many of X’s ads are still labeled, this makes the unlabeled ones even harder to spot.

It’s unclear if the issue is a glitch with X’s advertising platform or a deliberate change intended to deceive consumers into believing some ads are regular posts from accounts they follow.