I believe the original suggestion came from @Netflix_Addicted so yeah. I didn't like the suggestion at first because you could build around the bottom of the island to eliminate campers. But, my opinion had changed. Earlier today, I encountered a hacker and I paniced, but he was 20 seconds behind me. I managed to buy a piece of TnT and crossed the bridge over to the next island and built a three high pillar. I hid the TNT behind it and got the perfect timing and knocked him into the void. The next game I encountered another hacker and tried this again; and it worked again! However, before the hacker fell all the way down he teleported back up. I hope that's enough explanation as to why thus should happen.