Did he do anything besides the Stanford Prison Experiment that I just don't know of? Because if that's all, I'd be more inclined to say that he's just stubbornly wrong rather than evil. But maybe you know something I don't
The only thing useful about that study was his vile behavior and how everyone at the university went along with it.
Hell, he was still working at a University in Palo Alto just a few years ago.
Even after admitting all the horrible shit he did, he kept teaching (and probably kept banging his students like he did back then) until only a few years ago.
I remember some popular YouTuber ran an experiment trying to re-create the conclusions that Zimbardo had come to. The results contradicted his conclusions and they confronted him. He continued to defend his experiment. He seemed like a rather stubborn man.
I don't think anyone has been able to recreate his experiment. He's accused of manipulating it to fit his narrative. He denies these accusations, of course.
Zimbardo is part of a generation of psychology that struggled with why modern European people did a Shoah. Or rather a generation that sought to confirm through experiment that the Germans were alright and it was really all Hitler's fault. Or at least a small number of evil Germans who caused the whole mess.
It's auspicious to bring this up now because just watching the news these days makes a fool of Zimbardo.