I found the TNT glitch where TNT still works:

1. place a redstone torch on the ground
2. place a TNT block next to it

You've probably blocked placing TNT blocks, however, when you do it this way^ the TNT block will instantly ignite. The computer wont recognize it as TNT_BLOCK, but as TNT_BLOCK_IGNITED. <- The names are a quick guess btw.

Hope you fix it before any griefers read this! xD