I once outed a guy who called me a "deformed barbie" to his girlfriend. I sent her the screenshots of what he would say to me: he would BEG me for nudes and I was like nah you're straight so he admitted he was gay
Well, I have beaten up a guy really bad who punched my sister. Sadly, I wasn't there when it happend, but when I saw her and somebody had filmed the whole situation on top of it, I really lost it. I waited for him, confronted him and then the party started.
I have never been so angry in my life, especially after watching the video.
He wanted to sue, but he didn't.
Other than that, I have never felt the need for revenge.