I was sieging a player, JoeSchmoo21405, when a strange glitch happened that sent me straight through one of the stone bricks. I dig a little area outside of his claim and built a dirt piller to get on top of his small stone brick box, when I jumped from the dirt pillar onto the box I went straight through the roof of the box and appeared inside it. I was trapped inside due to the siege, so I killed him so I could teleport out. I apologized and took nothing from the unlocked chests that were inside the base, due to me not knowing what happened, or how I got inside. I returned the items he had on him when he as inside, which was a wooden pick, and some cobblestone. I feel like this could have been some odd glitch with lag or whatnot but I still have no idea.
Time to paint the Path of Glory in the Blood of those who are not worthy.