That sight costs $520, you could practice a lot for that amount of money. Also, Why? What advantage does it give you? It seems to me it would be a hindrance to proper shotgunning, plus adding weight and bulk to your gun. Now I'm not knocking EoTech they make great stuff, but they are only advantageous in certain specific times(very close range, on a short rifle).
The only power any government has is the power to crack down on criminals. Well, when there aren't enough criminals, one makes them. One declares so many things to be a crime that it becomes impossible for men to live without breaking laws.