Randi Zuckerberg, sister of Mark Zuckerberg and former marketing director of Facebook, posted a photo to her Facebook. It was supposed to be visible only to her friends on FB. She was less than thrilled when someone reposted it to Twitter. That someone is Vox Media's Callie Schweitzer who tweeted the photo to her more than 40,000 followers. And now the pic (which you can see … [Read more...] about PHOTO: Mark Zuckerberg’s sister angry that Facebook pic goes viral