When it comes to Facebook and other social networks, many students don't realize that not only do they need to be concerned about what they post on their profiles but also what other people post.
- The Wall: Your Facebook profile has a "wall" where your friends can post whatever comments they desire. MySpace has a comment section for the same purpose, and I'm sure the other networks have similar things. You can, of course, delete these comments but they will still be up for some time before you see them and delete them.
- Tag, You're It: As one of my students pointed out, people can post pictures of you on Facebook and tag it with your name. Those pictures then get linked to your profile as "tagged by others." And, of course, they don't need your consent to do this (at least, as far as I know). Just think of all the compromising photos that could be put up without your approval!