I have suddenly thought of an WONDERFUL idea!
When someone lags, the screen turns black, they cannot shoot, they are unkillable, and they cannot move. They can still chat, but that's all. If you play games like Assault Cube you will know what a mean. Why do that? Because I just hate it when my health is something like 1 and then I fall down a cliff cause of lag. If you stop moving, then you CAN'T accidently kill yourself! If your screen is black, you cannot spy on people. Now that is a GOOD idea!