As Koobface has proven, stealing biscuits can get malware distributors a long ways.
Another technique and tool has just been posted to abuse stolen biscuits, much like the Koobface worm, and it supports changing a wall without the password. The author claims to have just completed “FBController – The Ultimate Utility to Control Facebook accounts without the Password”.
Be aware that downloading and executing code from untrusted sources is always a problem, and please do not fall for the ongoing phony video codec or software update ploys.
Update – a cnet writer finds the techniques interesting.