Mark Zuckerberg's sister angered after family Facebook photo goes public

• Tweet

The confusion around Facebook's oft-criticized privacy settings hit close to home for founder Mark Zuckerberg, when his sister noticed that a photo she had meant to be private went public.

On Christmas Day, Randi Zuckerberg posted a Facebook photo of her family -- including Mark -- reacting in mock surprise to the company's new Poke app. When Callie Schweitzer, Vox Media's director of marketing, saw the photo at the top of her feed, she assumed it was public and promptly tweeted it to her followers.

Surprised and unhappy, Zuckerberg lashed out at Schweitzer in a since-deleted tweet: "@cschweitz: Not sure where you got this photo. I posted it only to friends on FB. You reposting it on Twitter is way uncool."

Schweitzer immediately apologized and deleted the offending tweet, explaining that she thought the photo was meant for everyone to see.

@cschweitz would really appreciate if you would delete the original tweet where you posted the photo. No need to spread it further. Thanks!

— Randi Zuckerberg (@randizuckerberg) December 26, 2012

@randizuckerberg I'm just your subscriber and this was top of my newsfeed. Genuinely sorry but it came up in my feed and seemed public.

— Callie Schweitzer (@cschweitz) December 26, 2012

Zuckerberg later deleted her Twitter criticism after the two figured out that Schweitzer was Facebook friends with another Zuckerberg sister.

She issued a warning to other social media users, asking them to be wary of "digital etiquette."

Digital etiquette: always ask permission before posting a friend's photo publicly. It's not about privacy settings, it's about human decency

— Randi Zuckerberg (@randizuckerberg) December 26, 2012

Maybe Randi could stand to pick up a few tips from her brother?