Am I the only one who sees this as EXTREMELY childish?
You're not alone although I probably wouldn't go so far as to call it "extremely" childish. Just misdirected maybe.
I can see why some want to do it, though it's not my cup of tea. I don't think this kind of "attack" does anything but reinforce to JWs who witness these things to think that "apostates" are raving lunatics and demon possessed.
Ex-JWs have real issues and concerns with the religion and how it still affects their lives and there are ways to combat the control the WTS has on our family still in, but resorting to pranks to show the WTS that you're on to them doesn't do anything to help you get your family out or change JW family/friends from treating or thinking about us any differently.
I think we need to realize that we can hurt only ourselves individually with some of these "anti-JW/WTS" antics. Remember, we used to be JWs...were we all that bad and evil? Most JWs are just misdirected and decieved. It's the WTS that's the enemy, not the followers. I think our efforts should be aimed at freeing the oppressed. The more people that learn the truth about the "truth", the more it will hurt the WTS as members leave and new recruits dry up. It's not a battle that will be won overnight, it takes time. Maybe another generation or two. But it can and will happen if we work to instruct and enlighten instead of attack and insult.