Facebook has begun running a “privacy checkup” campaign that prompts users on the desktop version of the website to check that they’re sharing their posts with the right audience – for example, “Friends,” or some specific list, instead of just everyone. Users tend to report seeing this new pop-up appear when their privacy settings are currently set to “Public.”

The reminder, courtesy of screenshots found on various blogs including Slashgear and Sociobits.org, as well as on Twitter, reads:

Hi [name] – Sorry to interrupt. You haven’t changed who can see your posts lately, so we just wanted to make sure you’re sharing this post with the right audience. (Your current setting is Public, though you can change this whenever you post.) Learn more. Who do you want to share this post with?

People started to notice the pop-ups at some point last week, when they received minor press coverage. (We’ve asked Facebook to confirm when the campaign officially started, and they told us it was actually a few weeks ago.)

Though a seemingly minor informational prompt, the addition arrives at a time when Facebook is facing increased competition with a bevy of mobile, social services offering more private sharing – WhatsApp being one which the company notably acquired for a mind-boggling $19 billion.

Earlier this month, Facebook also rolled out new private photo-sharing tools that offer an easier way for users to select specific people to share a photo album with via Facebook’s News Feed. The selector itself is reminiscent of Snapchat since it also lets you pick individual friends who can see your private photos.

As Facebook has essentially tapped out its growth potential in developed markets where it has a presence, the company has been looking to fund global initiatives to connect more users to the web, as with Internet.org. It has been looking to gain more of users’ time on mobile through acquisitions like WhatsApp, plus its own internally developed apps like Paper.

It’s also interesting to see Facebook shift its course to refocus on more private sharing in this post-Snowden era where users are beginning to feel more wary of the public nature of online sharing. Meanwhile, a new generation of users has been born into a world where their identities and private lives were already over-exposed by mom and dad while still in the womb and learning to crawl. It’s the perfect storm for a backlash against public socializing.

Facebook has also said it may even roll back on forcing users to interact by way of their “real” identities. That’s a radical shift for a company whose vision had been rooted in this idea of openness and transparency — efforts Facebook claimed would make the world more connected, which it determined was a good thing overall. (At least, that’s how it once justified making everyone’s private content public by default, while offering privacy controls so complex that users couldn’t figure them out.)

The reminder showing up now that – hey! you’re still posting publicly! – is an example of Facebook’s changing values in action. But the company is nothing if not adaptive. It changed the rules before and can do so again.

Note: post updated with Facebook comment after publication; Image credit: Twitter user Brandon Wall