Doesn't this question answer itself? It worries me that you don't think it does. There's investigating - because someone is paying you, I assume - and then there's stalking, where someone isn't paying you. The line is paying you.
So if you're jerking off outside someone's window while they undress, you might want to think, who's paying me right now?
The answer is no one. Unless you're a landscaper. Then it's possible the person you're jerking off to is paying you, and that creates an intense and delightful feedback loop that should make your orgasm as intense as if you pressed really hard on your prostate.
Short Answer: This is a side note. I was playing hockey today, and in the dressing room, someone had written, "I fat penis. I eat poo." I was so happy until I realized that the person had just been inconsistent with his uppercase/lowercase decisions, and it actually read, "I Eat penis. I eat poo." I was devastated. (I think maybe I need to create the character of a fat penis that eats poo to soothe myself.)