Privacy in Social Media

Have you posted to Facebook lately? I've become a FB window shopper these days. I don't post much but I continue to be surprised by what other people post. It makes me wonder what my nieces and nephews will post when they have their own account. Just one ill-thought out picture can ruin a person's life. What steps do you take to inform your students about the dangers of social media? How do you keep yourself safe? Do you rely heavily on privacy settings or limit your friends?