Revenge doesn't go far enough. Revenge suggests something transactional. From the start, for their very nature, these people deserved suffering and only suffering. As Cioran regretted the immutable stain of birth, I regret the stain of a prelude to the carnage.
He was the principal of an alternative school nominally dedicated to children with "behavior problems" that included gangsters, public masturbators, attempted murderers, and people who were insufferably weird, autistic, or queer. It was basically a prison.