Google is banning the promotion of pornography sites on its ad network, CNBC reports.

The search giant announced the policy change in an email, which was sent to the companies that would be in violation of the new policy. Here is part of that email:

Beginning in the coming weeks, we’ll no longer accept ads that promote graphic depictions of sexual acts including, but not limited to, hardcore pornography; graphic sexual acts including sex acts such as masturbation; genital, anal, and oral sexual activity.

When we make this change, Google will disapprove all ads and sites that are identified as being in violation of our revised policy. Our system identified your account as potentially affected by this policy change. We ask that you make any necessary changes to your ads and sites to comply so that your campaigns can continue to run.

While a company spokesperson said Google has had tight restrictions on the adult category within its AdWords platform from some time, there’s no denying that “porn” and sex-related searches are among the most common on Google’s search engine. According to the company’s AdWords Keyword Planner, searches for the words “porn,” “sex,” “porno” and “free porn” almost reached 351 million in May alone.

As a result of this AdWords policy change, it’s unclear how Google’s bottom line will be affected. We’ve reached out to Google to learn more, but in all likelihood, we will know more in the coming months when the company posts its quarterly earnings reports. Google will announce earnings for its second quarter of fiscal 2014 on July 17.

It's also unclear how this will impact pornographic sites. We haven't been able to find any estimates for how much of their revenue comes from AdWords.

At least one high-ranking member of the adult industry was surprised by Google’s decision.

“I was caught by surprise,” Theo Sapoutzis, chairman and CEO of the AVN Media Network, the world’s largest consolidator of adult content, told CNBC. “I was one of the very first advertisers for AdWords back in 2002. It’s something that’s been [untouched] for 12 years, so you don’t expect change is going to start happening.”

The Morality In Media group, which calls itself “the leading national organization opposing pornography and indecency,” claimed it was able to persuade Google’s decision by meeting with the company and listing it on its 2013 and 2014 Dirty Dozen Lists because of “their involvement in and profit from pornography in Google Play, Google Ads, YouTube and more.” Google, however, said, “We made this decision as an effort to continually improve users’ experiences with AdWords.”

Now, the next question is if Google will expand this effort to block the promotion of adult sites by applying this policy to its search engine.