Where do Facebook and MySpace come in?

I just came across this article after I finished my last blog posting:

Facebook Welcomes Companies And Developers

As Facebook welcomes an open-platform strategy, more companies gain access to it. As it is, companies can access Facebook to look at your profile (the same goes for MySpace). I have heard of cases where employers check the pages and candidates are removed from the list of potential future employees. This is meant as a warning to be careful of what you broadcast for the world to see about yourself. There are privacy settings that you can use to guard yourself from being viewed by everyone. Regardless, ask yourself is it really something you want everyone to know or is it just something you do to be cool? Either way, it may get in the way of your job searching and remember that some day you are going to "grow up."