People whose personalities revolve around harassing others in whatever way (physically, socially, psychologically, sexually, intellectually, financially, etc.) are the worst people I've had to deal with. They have such awful personalities. Imagine having a personality that revolves around harassing people. Imagine having the kind of personality that's all about targeting some individuals, following them around, and messing with them frequently.
Imagine basically having "harrasser" as a personality trait. That's just who you are. You harass individuals. You follow them around just to torment them. That's your hobby. Out of all the hobbies you could pick, you've selected "harassing" as your main hobby. It's ****ing wild, man.
As someone who greatly values personal privacy, personal autonomy, and personal dignity, I cannot imagine dedicating much of my life to becoming as skilled as possible at harassing people, yet there are people who dedicate themselves to doing so. Blows my mind.