MENLO PARK, CA: Facebook is taking a stand on ad blocking as it changes how advertising is loaded into its desktop website in order to make ad units more difficult for ad blocking software to detect.

"Facebook is ad-supported. Ads are a part of the Facebook experience; they're not a tack on," said Andrew Bosworth, vice president of ads and business platform at the social media giant, in remarks reported by the Wall Street Journal.

The new initiative does not claim to be able to filter out all ad blocking but it makes the process so slow for those determined to block ads – "they would have to do a deep inspection of the content" – that the user experience is compromised.

"People who have the choice of seeing ads on Facebook and a slower experience would all choose to see the ad," Bosworth explained.

At the same time, the company is making it possible for users to more precisely control what ads they do see, via its Ad Preferences unit, whether those are interest-related or from particular brands.

"It just seems like a poor bargain to be forced to choose all or nothing. There's a middle ground," Bosworth said.

So, for example, users can now tell Facebook not to serve them ads from companies that may be targeting them, Advertising Age reported.

Specifically, users will be able to see those advertisers that have them on email lists and decline to receive their ads.

Bosworth argued that the moves would benefit both users and brands. "Advertisers want to make sure they're spending money in a way they think will be effective for them," he pointed out.

Data sourced from Advertising Age, Wall Street Journal; additional content by Warc staff