This worm posts a message on your wall saying something like "Hey, I can't believe you are in this video". The message can be anything like mentioned above and below.
Some more messages are like these:
hey _your facebook name_ i can’t believe youre tagged this vid
hey _your facebook name_ you look so stupid in this vid
hey _your facebook name_ why are you in this vid
When the user clicks the link curiously wanting to checkout the video, it opens up a video screen. When the user clicks the "Play" button on the video player, the problem starts. The play button does not starts playing the video but it displays a message - "Select Address bar. Press Ctrl+V. Press Enter". When the user press Ctrl+V (which stands for Paste) and press enter, this worm gets the list of all your friends, and posts the same message like you got on your wall, to your friends' walls. But how, you wonder. Well, when you click on the "Play" button, it generates a code which contains the list of your facebook friends, and copies the code in the clipboard Then when you paste it in the address bar, it posts the same message to all your friends. And when your friends do the same, it gets spread more and more.
It is not yet know what data other than the victim's friend list this worm gets access to.
I would advice you not to get too curious and click any suspicious link appearing on you post, or in your messages. You should prevent yourself and your friends from being victim of hackers.
If you read this post, then spread the word among your friends and help them before they fall in this mess.
I, myself have not seen this worm in action. If you have some such experience, share with us. Whether the worm exists or not but better be safe.