I been playing with the new command /blockdata for lock chests in my multiplayer worlds, but with my friends we notice that no matter if a chest is locked with /blockdata, anyone can break the chest and grab your things.

I really think that this is a bug, because I see it useless at all the fact that you can lock your chests but if anyone breaks the chest, anyone can grab your things anyway.

The bug is in both, creative and survival game modes.

Down here there are a few pictures showing the problem.