So, I was making an iron farm and it required a lot of chests. I placed 32 chests down, and went to get some more wood, however my game froze and I had to shut down my pc. When I came back to my world, the chests I placed down were there but I also had 32 chests in my inventory! It could be a problem that has to do with an, overload maybe? I don't really know, all I know is that people could perhaps use this for precious items like dragon eggs or beacons (which is bad). I also have no idea how my game froze, its most likely a problem on my end. (The reason why I have 30 chests in the screenshot is because I placed down the remaining chests)

Edit: There is another bug report similar to this, MC-63. Thanks Brain81505 for the info

Edit 2: Looks like everything is resolved!