A month before unveiling a major new search feature, Facebook changed its privacy policy to remove the ability to opt out of search results.

I noted this in my piece yesterday about the privacy implications of the new feature, Facebook Graph Search, but thought it worth highlighting further. Graph Search, which isn’t yet widely available, allows users to search their Facebook network with queries like “restaurants my friends like in London” and “friends of my friends who are single and live in Hong Kong.” It’s a major new initiative for Facebook that could provide new opportunities for advertising and bring more value to the data it stores about users.

But before launching Graph Search, Facebook last month pushed through changes to its privacy policy that will make it easier to implement the new feature. The new section, which went into effect on Dec. 11, 2012, reads:

When you hide things on your timeline, like posts or connections, it means those things will not appear on your timeline. But, remember, anyone in the audience of those posts or who can see a connection may still see it elsewhere, like on someone else’s timeline or in search results. You can also delete or change the audience of content you post.

At the time of the change, Facebook product director Sam Lessin said “a single-digit percentage of users” had opted out of appearing in search results on Facebook. The site has more than a billion users, so 1% is 10 million people. The company didn’t respond to inquiries today.

Though users can no longer opt out of search results entirely, Facebook still lets people control who has the ability to see specific updates about them in search and other parts of Facebook. Many users have found those privacy controls confusing, and another change implemented last month was intended to simplify the options.

The issue is hardly academic. Just last summer, the company settled with the US Federal Trade Commission for making changes to its privacy policy that the FTC deemed “deceptive.” The issue then was that information users had posted to Facebook was viewable to a growing array of people who weren’t originally supposed to see it. Privacy advocates argued in December that removing the ability to opt out of search amounted to the same thing and violated Facebook’s settlement with the FTC. I’ve contacted the FTC but haven’t heard back yet.

“Many people posted stuff on their timelines that they did not expect to be publicly searchable,” Marc Rotenberg, executive director of the Electronic Privacy Information Center, told the Wall Street Journal. Sam Biddle of Gizmodo demonstrated this dynamic with Graph Search queries like “people who like hating when black people say things that you can’t understand!” and “men who like shitting my pants,” which turned up plenty of results.

The FTC settlement mandates that Facebook submit to annual privacy audits for 20 years and pay $16,000 per day for any violations. It also requires Facebook to “obtain the user’s affirmative express consent” when adding a feature that “materially exceeds the restrictions imposed by a user’s privacy setting.” The changes to Facebook’s privacy policy in December may have given Facebook clearance to debut Graph Search, although for now, at least, the company is also asking users to sign up for the feature.

Finding previous versions of Facebook’s privacy policy is surprisingly difficult. The company doesn’t allow services like the Internet Archive’s Wayback Machine to “scrape” its privacy policy. I was able to find an archive of Facebook’s previous privacy policy, before the Dec. 11, 2012, change, here, thanks to a project still in development by the Electronic Frontier Foundation. Here it is in a more readable form, and you can read Facebook’s current privacy policy here.

Update (Jan. 18 at 11:00 a.m. ET): Thanks to Neil Kandalgaonkar, here’s a better view of how Facebook’s policies changed, including the company’s own “redline” of the changes.