Constant Mouse Speed for all Clients

I'm working on a game where the accelleration of the mouse determines the speed of the player.

 mouseDelta = Input.mousePosition - lastMousePosition;
 lastMousePosition = Input.mousePosition;
 Debug.Log (mouseDelta.ToString ());
 rb.AddRelativeForce (0, 0, mouseDelta.y * forwardSpeed);
 rb.AddTorque (0, mouseDelta.x * rotationSpeed, 0);

This is the code ive used which appears to work fine. My problem is that nothing stops the user from increasing thier mouse sensitivity / DPI to move faster within the game. As my game is multiplayer it is important to keep things fair and have people move at the same speed. I understand that it would not be possible to control the user's mouse DPI or OS sensitivity but was wondering if there was a way within unity to force the mouse sensitivity to a constant or maybe calculate a modifier for "forwardSpeed" and "rotationSpeed" based on the users current sensitivity.

Thanks for any help, Liam!