If you’re invited to watch a movie on Facebook, realize that downloading a “special codec” or “media player” is ill-advised. It’s malware.
Example running right now:
Messages from Your Friends on Facebook, March 11, 2009
You have 1 Personal Message:
Video title: “Amanda is dancing on Striptease Dance Party, March 13, 2009! We’re absolutely shocked!”.
Proceed to view full video message:
Message ID: FB-7n1cqla9sgguzde
2009 Facebook community, Message Center.
When you try to view the “video”, you’re asked to download and run a “media player”. That’s the malware part.
This has been reported to Facebook.