Users of the browser—that is to say, well over half the people who surf the web—will no longer see any ads at all on websites that regularly throw up such annoyances.

The move was first floated back in April last year. As has been the case ever since then, many people in the media industry are concerned about the implications.

The issue is whether Google—itself one of the very biggest players in the online ad market—will use the move to favor itself and disadvantage rivals.

The company is basing its decisions on which ads to block on standards set by the Coalition for Better Ads that studies which ads “fall beneath a threshold of consumer acceptability.” According to The Wall Street Journal, members of this coalition report that Google came up with the coalition and performed most of its research.

“It’s important to note that some sites affected by this change may also contain Google ads. To us, your experience on the web is a higher priority than the money that these annoying ads may generate—even for us,” Chrome Vice President Rahul Roy-Chowdhury wrote in a blog post.

However, the Journal notes, other coalition members said the blacklisted ad formats “generally don’t apply to Google’s own business.”

The proof will be in the pudding. And, if Google wants to avoid adding to its various antitrust woes, it would certainly be best for the company if this ad-blocking measure doesn’t turn out to unfairly benefit it.