In one of the more ironic tech stories of 2012 Randi Zuckerberg, former Facebook director and sister of Mark, has been tripped up by the social network's ever-changing privacy settings.
The Silicon Valley heavyweight had posted a family Christmas photo to her Facebook page thinking it was only viewable to her friends.
However, as her sister was also tagged in the photo and Randi hadn't specified that the photo should be viewable only to her friends, it also appeared in the news feeds of those tagged.
The photo, which simply depicts friends chatting around a kitchen table, was picked up by her sister's pal, marketing director Callie Schweitzer, who assumed it was for public consumption and reposted it to Twitter.
The tweet prompted an angry response from Randi Zuckerberg, who told Schweitzer that the repost was "way uncool" as "I posted it to friends only on FB."
In a further tweet, Ms Zuckerberg vilified the offending party a little more: "Digital etiquette: always ask permission before posting a friend's photo publicly. It's not about privacy settings, it's about human decency."
Randi, who runs her own media company and produces a reality TV show about life in Silicon Valley, could have avoided the unauthorised share by customising the privacy settings during the upload process.
If she had selected 'Custom' from the picture upload settings menu, and then selected 'Friends,' her sister's pal wouldn't have seen it in her news feed.
As many responders to her tweet have pointed out, perhaps this easy-to-make mistake is something she could take up with her brother, you know, the CEO of Facebook.