Recently, I've been having this urge to hurt people's feelings and enjoy it. How can I stop this?

This was because some of these people have tried to persuade me to become loyal to them, but they invaded my rights and my sense of autonomy by researching info about me so that they know all of my weaknesses. I can't ever forgive them and I don't really care if they get extremely hurt. It's not my loss if I lose any of them, and it's not their loss if they lose one friend. I actually am an extremely nice person but I become willing to destroy whatever ties I have with people who I feel try to control me, use me, or make me make difficult decisions so that they get profit from it. It is also coupled by a sense of betrayal because they aren't what they say that they are.