Hiding Behind Social Media

I just read this article on Bit Rebels called Facebook in Real Life.  The article includes a video (which is hilarious) showing how ridiculous some of our social media (specifically facebook) habits really are.
Now, once you get past the ridiculousness of the video itself the idea really does have a point.  On Facebook you actually use your real name, your real face, real pictures of you, your real job and email address are listed.  You don't hide behind a screen name or a buddy icon.  Its our real selves there on the page.  However, Facebook is losing more and more popularity as Twitter continues to get stronger and stronger but on Twitter you can still have that aspect of anonymity.  Your 160 character bio doesn't have to have any information about you at all.  And your mom won't be posting photos of you in the Christmas sweater your Grandma knitted you.

Why do we use social media if we're simply going to spend our time hiding behind our pseudonyms and screen names?  Another big example of this is RPGs for example, World of WarCraft.  WOW is yet another place online where you do not have to be yourself, you present yourself with an Avatar who probably does not look a whole lot like you (it might not even be human) and yet people build relationships with one another through this without ever knowing each other's real names. 

What does this say about us?  Are we so ashamed of ourselves that we are not willing to own-up to our own beliefs and ideas?  Is the world's reaction to our true selves really going to be so cruel that we can't handle it?