Fantasy of being the ultimate predator
Being a vigilante has a certain degree of hypocrisy, I realize. Some people will say, "Who are you to judge?", but I see things the way I see them.
To me, the idea of being a gray knight with super powers who could punish people who torment others, sounds very fun.
If I were stronger than "wrong doers" who break laws, then they'd be the most vulnerable, as I believe they should be.
Even if I were to blackmail a criminal, they couldn't go to the authorities, unless they wanted to go to jail.
I have a taste for poetic justice sometimes.