In a way, social media is like smoking — but instead of being bad for your health, it’s bad for your privacy. There’s another striking similarity between the two: just like second-hand smoke is a thing, affecting those who might not even smoke, social media might also affect the privacy of those around you, even if they’re not users themselves.
The new study from researchers at the University of Vermont and the University of Adelaide gathered more than thirty million public posts on Twitter from 13,905 users.
The first concerning find is that it only takes 8 or 9 messages from a person’s contacts to be able to predict that person’s later tweets “as accurately as if they were looking directly at that person’s own Twitter feed”. In other words, social media information about yourself can also be derived indirectly.
“You alone don’t control your privacy on social media platforms,” says UVM professor Jim Bagrow, one of the authors of the study. “Your friends have a say too.”