Anyone can screw over anyone, or am I just paranoid?

This is not a troll post - hear me out. 

I'm sure you guys have all at some point experienced the toxic, ultracompetitive, jealousy-filled recruiting environment during undergrad. Let's say Chad is in the interview process for x firm and Joe for whatever reason wants to see him fail - what's stopping Joe from going on a VPN and anonymously emailing the office recruiting head falsely claiming that Chad committed some sort of inexcusable offense (sexual assault, racial abuse, etc.)? Joe can do this with absolutely no consequence (as opposed to openly defaming someone) Think about it - in an age where firms are obsessed with their reputation, would they really take a risk and potentially hire Chad, even if there is absolutely no proof? From the firm's perspective, it's much safer to just pull the plug on Chad's candidacy and keep it under the rug, especially if it's a smaller firm. Chad wouldn't even know it happened. And while Joe is at it, what's stopping him from doing one better and mass sending that email out to every firm Chad has a remote chance of interviewing at? Sure, some firms might discard it as spam. But for those that don't, Chad's reputation has been destroyed irreversibly. And finance is a small world. 

I would never do this to anyone else no matter how much I hated them. But other people? The one thing that has never failed to surprise me is how low some people are willing to stoop just to see someone fail. What's stopping someone from doing something like highlighted above other than perhaps their own moral compass? I've never actually done anything that could get me in trouble, but like most people, I did make a few "enemies" during my undergrad. When it feels like the only thing stopping someone who dislikes me from taking everything I've worked for is their own moral compass, it's a terrifying feeling. Am I just being paranoid?