Hello,
Don't know if it is a bug but players with different FPS move by different speed.
I use FreeCamera.
I have got 60 FPS and I move about three times slower then other player with 20 FPS.
That's weird because players with lower FPS should move slowly. I guess there is some speed compensating code.
Also if player is for some time in another browser window and switch to game immediately holding move button he move for a while by huge speed.
Sorry for my English.
Thanks!