Sit him down in an electric chair.
Glorb, I'll tell you what I would do, being the strange and bloodthirsty, but harmless and generous, person I am: Play mind tricks on her. Draw smiley faces on the backs of Post-Its and stick them to the outside of the window while she's asleep. And add more and more, one at a time, every day. At least, soon there will be too many Post-Its for her to see you.
For effect, write numbers on them and count down from twenty or more. For Post-It zero, draw an evil smiley face and leave it inside a small present with an egg by the front door, and start over.
I don't think it's illegal. It's not graffiti or destruction of private property, it's not necessarily littering, you're not harming anyone, etc.