The power of social networks like Facebook and Twitter comes from their ability to quickly share information about your life with other people. But along with that ability comes the risk of sharing sensitive information with the wrong people, and that risk increases as your network grows well beyond your core circle of friends.

Using Twitter and Facebook effectively takes more than discretion; you should know how to tweak the settings for these services so that you have full control over who sees what on your Facebook page or on Twitter. In the two stories linked below, and in others to come, we'll cover both sides of the coin: how to use the tools at your disposal to keep your profiles in check, and how to handle the etiquette side of the equation, as well.

The garden-variety freshman may not have much to worry about, but it's a different story if you--as many people are increasingly doing--are using Facebook and Twitter not for updates about your meals, pets, and drinking binges, but for professional purposes. So we've outlined here a handful of common disastrous scenarios in which one (or both) of these social networks was misused, as well as the best way to prevent or remedy the problem.

But in the end you'll find that the fundamental lesson is invariably the same, and that's to remember the golden rule of all social networks: Never forget that the whole world is watching.

Now go on to: