I saw a good prank of revenge at a CO game a couple of seasons ago. A guy named Jorge (well known) was mad about a beach ball that was being batted around the stands during the game. He finally was able to grab it and tossed it off the top, out of the stadium while the crowd boo’d him.
The next week, at an obviously pre-determined time, about 25 kids started batting 25 beach balls around the stands. Jorge was speechless as the entire crowd laughed their butts off at him. It was a good one, and very well planned.