peaceful survival bug STRANGE!!

ok... so I whent on to my faction on peaceful survival (I am the owner) then as me and my friend noticed all are locked chests was unlocked and ALOT of stuff missing I KNOW that some one hacked are faction and no one had access to my laptop I think it was around the time of the name changing update I hope you see this because I do not what to find/bye all that stuff agene and this to not happen any other time. I have one suspect on who on the day it happened the player tacoking left my faction (I trusted him) but I hope he did not please read this -kobiepops (oh and my faction name is meowness)