Destroying ice or snow will let TNT work only on man made areas. Creepers also do not destroy land that is not man made.

A quick way to try it is pick up a snowball or destroy an ice block. Throw it and wait for night. When night comes go toward a creeper and have it blow up. Nothing happens for me. It damages me, but not the land around it. I have 54 blocks of TNT or so that I can't use destroy land that is not man made. I have noticed this bug for a long time and thought you should know. Please fix it. Thanks