I've been thinking about it a lot lately. There is no one in particular I am seeking vengeance against, but it's good to have a list of ideas. Here are four for your consideration.
1. Go to northern New Mexico, find some sheep herders and bring them to wherever the person against whom you seek satisfaction works. Have a sheep shearing party. Sheep are smelly loud beasts and the person will soon regret whatever it is they have done. Afterward you can make sweaters and have a matanza.
2. Purchase one hundred boxes of allergy pills, five gallons of pool cleaner, vinyl hosing and assorted coffee filters and camp stove fuel. Place items in trash bags and deposit in enemy's back yard. Call drug task force and report clandestine methamphetamine lab. Don't get caught transporting these items, lest ye be charged with manufacture of a controlled dangerous substance. [I wouldn’t do this; it’s probably construed as a felony in most courts.]
3. Buy a cow. Place cow in enemy's office. Feed cow. Smacking of cow lips will soon drive them mad. Large amount of cow dung will also have crazing effect. Note, this does not work if you share an office.
4. Hijack space ship by placing mind controlling bugs in ears of crew members. Threaten to use planet building Genesis device as weapon. Quote Melville. I saw it in a movie once. It didn't work out to well but the principle is sound.