Google has started taking action to remove Chrome extensions that violate the company’s terms of service, in particular serving users unwanted ads.

The Wall Street Journal reports that Google has removed two Chrome extensions from its Web store — ‘Add to Feedly’ and ‘Tweet this Page’ — after they were updated to include code that caused the unwanted appearance of ads.

Amit Agarwal, the developer behind the ‘Add to Feedly’ extension, described how he sold it for a four-figure sum. A month later, the new owners of the extension pushed an update to the Chrome store that “incorporated advertising into the extension.”

Agarwal describes the situation that the more than 30,000 users of the ‘Add to Feedly’ extension faced after that happened: “These aren’t regular banner ads that you see on web pages, these are invisible ads that work the background and replace links on every website that you visit into affiliate links. In simple English, if the extension is activated in Chrome, it will inject adware into all web pages.”

In December, Google announced its intention to crack down on extensions in the Chrome Web Store, as it dictated that extensions “must have a single purpose that is narrow and easy-to-understand.” Part of this move was to put a stop to extensions meant to serve a purpose such as displaying product ratings and reviews, but ended up injecting ads into Web pages too.

The problem of forced ads in Chrome extensions seems to have become so pervasive that Google has noticed it and is taking action to make sure user experience isn’t compromised. After all, such multi-purpose extensions — in particular those with ads — can crowd the Chrome browser’s UI and slow down Web browsing.

Headline image via Kimihiro Hoshino/AFP/Getty Images