Ten gallons of gas. Go to their house about 3 a.m. if it's dark and no lights on. Quietly circle the house with the gas. Put a bunch on and around the front and back door so if they rush out they'll walk into it. Spill some roofing tacks in front of the doors, too, in case they're barefooted. Light it and walk away quickly.
In Chicago, that's called "Jewish Lightning"- ten gallons of gas, and an Israel light.
