I was playing with a friend on Minecraft 14w32d and I got disconnected with a io.netty.handler.timeout.readTimeoutexception. When I connected back on there was a second copy of me with my exact skin and everything. I got kicked off again not too long after with the exact same error and sure enough when I connected back on there was another copy of me where I crashed off.

We decided to upload the world to my server and try that except the exact same thing happened except it happened on his side.

You can attack these glitch players and if you kill your own "clone" your game will crash. I do not have a crash log because I didn't crash, my friend did and we didn't think of saving the crash log.

After a while the server will eventually catch back up and all players will see a "Left the game" message for all the "clones". That player will disappear from the TAB list except they are still in the game and all other players can see them.

For the record I can run a 1.7 server perfectly fine on my system and friends can connect to it with no lag at all. So what is going on?