In mid-December 2018, Facebook published a public page intended to explain how its system works and answer questions users might have. “Facebook Advertisers: Who’s Reading Your Ads?” The company asked users to send questions using the form on the site. In mid-January, Facebook took action on this form, removing its ability to see which advertisers are running ads in relation to any particular keyword.

The Facebook Ads API, which lets users and advertisers look at what people are reading, and for what reasons, has three options:

Publishers (like bloggers or publishers) can see which specific posts have been viewed

Publishers can see any ads served to those posts on the site or in an app, from the target advertiser’s campaign

Publishers can also see any ad appearing that anyone is viewing on the site or in an app, from the target advertiser’s campaign

Why remove these tools?

One reason for the removal could be that Facebook is looking to limit the amount of information advertisers can access about specific users’ browsing history. The Facebook Ads API is an access point for Facebook to share information about who’s reading ads, in ways the company previously did not publicly discuss. A Facebook representative declined to comment.

Facebook already has similar tools for advertisers to see how its ads are targeted, called Targeted Actions API. The target audience is a name you assign to yourself on the site. The API also shows any users who had something happen at the same time that you saw your ad. This tactic, referred to as inference targeting, is controversial among privacy advocates.

These two sets of tools allow Facebook to tag disparate ads, even those that haven’t been published on the site or had any interaction with individual users. Take, for example, the ad for a business based in Chicago, targeting people who live in Washington DC. At one end of the spectrum, Facebook posts a broad-cast ad targeting broad-spread users, possibly based on name, city, state, ZIP code, zip code, interests, and demographic information. At the other end, Facebook uses its targeting tools to target business based on the target city, county, ZIP code, zip code, interest, demographic, and city (click on all these bullets to view the number of each) of a specific website or mobile app.

The Instagram API, in combination with a similar tool for videos called IGTV API, allows you to sort through different types of ads and identify specific content. Google’s YouTube API also makes it possible to correlate AdWords and ad buys with user activity. As more and more sites add the ads-as-content to their site, it should be easier to do targeted ads without violating the terms of service agreements the site must abide by. (YouTube has also been criticized for a system that makes user activity on the platform easy to track.)

It’s not yet clear whether this change is from a change in the way Facebook is building the API or from users’ request. Even though Facebook has said in public posts that the API is open, from a privacy perspective it may have been in user’s interest to see more information, especially when focusing ads on a specific individual. In an earlier statement, Facebook said that it had been “transparent with the community about what we’re doing with [the API] and how we’re using it,” although it did not respond to our questions about whether this was a case of changing the language in those posts.