Preben Ver Eecke from Roeselare noticed the security issue purely by accident. He managed to change somebody else's security settings without this person noticing.
Preben Ver Eecke decided to contact Facebook that decided to reward the 22-year-old student. Preben has not disclosed what his reward is: "I am an ethical hacker. I do this for the fun of it. I love hacking, but at the end of the day I'm interested in the ethical aspect. The reward was a nice extra!"