13. Be mindful about Facebook tagging

People differ on how open they want to be about their private lives on social networks like Facebook. They also vary in how wide their social circle is. Some only "friend" people who actually are their close friends. Others "friend" everyone, from co-workers and grandparents to strangers.

When you snap a photo with your phone and "tag" someone in it, you're showing the picture to all of his Facebook friends, and you don't know how open or selective he's been about "friending" people. Compromising pictures involving weird haircuts, drunkenness, partial nudity or silly behavior might not bother you, but you don't know how others feel about such things.

A good rule of thumb is to get permission to tag someone else's photo -- or at least never tag a photo unless you're sure that person wouldn't mind showing it to his mother, boss and children.