Software that blocks digital ads will cost online publishers nearly $22 billion in advertising revenue this year, according to a new study.

That figure comes by way of a new study from Adobe Systems ADBE and Page Fair, an Irish startup that caters to websites and advertisers looking to avoid those so-called “ad-blocking” practices.

The report notes there are nearly 200 million active users of ad-blocking software around the world, meaning that those Internet users have equipped their browsers with plug-ins that prevent the display of websites’ digital ads, which means lost revenue for websites that depend on advertising.

The Adobe report found that the practice of ad-blocking increased by 41% globally over the past year. The practice grew by 48% in the U.S., where roughly 45 million people used software to block ads in the year ending in June.

At the moment, ad-blocking software is less frequently used on mobile devices, with Fair Page reporting only 1.6% of ad-blocking traffic it tracked in the last quarter came from mobile devices. But Adobe and Fair Page report that software developers are working on ways to provide mobile users with ad-blocking capabilities. The new Apple AAPL mobile operating system, iOS 9, allows users to block mobile ads with the Safari internet browser, for instance, while both the Google GOOG Chrome and Firefox mobile browsers allow users to install ad-blocking extensions.