Weird chat conversation when world finished loading

I have experienced this issue on 2 worlds now. Basically when i log in to a world i am greeted with about 10 chat messages with a conversation people have had. I don't know what's happened here. Some ones are even a different language! Mojang Studios or some team at Minecraft please explain this creepy bug. 

 

Edit: It seems every time i log onto a server and then a world it happnes.