Facebook’s privacy settings can be confusing – just ask Mark Zuckerberg’s sister, Randi Zuckberberg.

Randi, who is the former marketing director of Facebook (FB), posted a feisty tweet Tuesday night scolding a Twitter follower for reposting a picture that Randi had originally published on Facebook.

“@cschweitz not sure where you got this photo. I posted it on FB. You reposting it to Twitter is way uncool,” Randi said in her tweet.

The Twitter follower, Callie Schweitzer, quickly responded.

“@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,” Schweitzer said in a tweet.

Randi then replied via Twitter that the reason Schweitzer could view the picture was probably because she was also friends with Randi’s other sister, so the follower could see tagged images of her.

Randi later deleted her original tweet to @cshweitz and also asked her to delete the tweet she posted with the picture of the Zuckerberg family.

Schweitzer kindly obliged, but Zuckberberg’s little social media mishap was already spreading like wildfire on Twitter.

Randi appears to have deleted most of the back and forth between herself and Schweitzer, but she later posted a telling-post about the incident.

“Digital etiquette: always ask permission before posting a friend’s photo publicly. It’s not about privacy settings, it’s about human decency,” Randi said in a tweet.

Yahoo