Eliezer credits Nick Bostrom with coming up with the idea of Friendly AI first (and indeed while Eliezer was indifferent to AI risk on the assumption that either superintelligences would be automatically supermoral or it didn't matter what happened). FOOM probably goes to I.J. Good, or SF (Eliezer found out about the idea of a technological singularity by reading Vernor Vinge's science fiction, and closely related ideas are decades older in SF).