im to noob just got the game like 3 weeks ago

i logged on after about 2 weeks and found my had a well placed tunnel to my diamond chest was very well hidden and surrounded by lava on all sides but a tunnel was dug straight to the chest. there was no sign of forced entry so he knew where all the switches were to get in and all he took were 2 stack of diamonds. i not asking for my stuff back i just hope this xrayer was cought already.