Minecraft Forums

Reason being if other player trys to trap someone.

The default is that any player can destroy any block in the game (other than bedrock, which is not a block that can be placed by a player). So, you must be playing with a host who has invoked "trust players" conditions themselves. Hosts generally do this to prevent players they don't trust from destroying their builds. It's the host's option, so if the host uses it to trap players, then I would suggest this is not a host anyone should play with... just find a different host.