I just came in and found 4 of my 6 graves "pilfered"! The headstones are still there, but they are blanks, and I cannot replace the names. The Roster shows only two of the six. I had no clue, until, out of the blue, some of my villagers picked flowers by the waterfall, and went to "Honor the Dead". I thought it odd, since I've not seen anyone do that so far in my game. They lay flowers at ALL the graves. I clicked on the first two graves, all was well, but the next 4 were empty, and the Roster had removed them. I've no idea how this happened, but it's kind of unsettling.