People have been complaining about Facebook privacy controls for years. Or, rather, the lack of Facebook privacy controls. Now, the issue is hitting close to home -- literally.

It seems Facebook CEO Mark Zuckerberg's older sister, Randi, wasn't too happy someone outside her inner circle saw -- and then tweeted -- a family photo she shared on her brother's social media site.

The photo shows her sisters using Facebook's new Poke app, which is similar to the popular sexting app Snapchat, on their smartphones. In the photo, Zuckerberg was looking on with a strange look on his face.

'Way Uncool'

Callie Schweitzer, director of marketing Relevant Products/Services and special projects at Vox Media, saw the photo on her feed. Thinking it was a public photo, she tweeted it to about 40,000 Twitter followers. The Zuckerberg sister wasn't too happy about that.

"Not sure where you got this photo," she tweeted at Schweitzer. "I posted it to friends only on FB. You reposting it to Twitter is way uncool. I would hate for a private photo of mine to be public and would never want to do same to others."

Schweitzer replied to Zuckerberg's Twitter message, saying, "I'm just your subscriber and this was top of my newsfeed. Genuinely sorry but it came up in my feed and seemed public."

Zuckerberg answered Schweitzer, saying she probably saw it because she's friends with her sister, thanked her for the apology and said she's "just sensitive to private photos becoming 'news.' "

Schweitzer ultimately deleted the photo and Randi tweeted about digital Relevant Products/Services etiquette. She wrote, "Digital etiquette: Always ask permission before posting a friend's photo publicly. It's not about privacy settings, it's about human decency."

Who's to Blame?

Is it about privacy settings? Are Facebook's privacy settings too confusing for even Zuckerberg's own family to figure them out? What happened here?

When you tag people in a photo, those images can also be seen by any of that person's friends. You can change that setting by creating a "Custom" option under photo sharing. It's not confusing, but it's not second nature, either.

So is Facebook ultimately to blame here? Or was it sister Zuckerberg's fault? Or is Schweitzer to blame? "Everyone likes to bash Facebook," tweets security Relevant Products/Services expert Dan Kaminsky. "But Randi Zuckerberg is right. Making the semi-private fully public violates social norms."