A frustrated security expert sick of being ignored by Facebook's people took to Mark Zuckerberg's personal Facebook wall to report a security vulnerability that allows strangers to post on anybody's wall.

Unfortunately for Khalil Shreateh, he isn't eligible for the $500 bonus that you usually get for reporting a security flaw because he broke Facebook's Ts & Cs by hacking its CEO's profile.

The bug has now been fixed, but here it is in video form, if you want to relive past glories:

More blips!

Post some blips on strangers' Facebook walls, if you like.