There are few lawful reasons for carrying a knife. Here is my plan. Anybody caught carrying a knife without lawful excuse shall be prosecuted. If they wish they can raise a statutory defence of lawful excuse in court (it shall be up to the defence to prove this lawful excuse). Anyone convicted shall be imprisoned for a minimum of five years (no early release). I am not a fan of prison. It's used far too often in this country and often for offences that could be better served with other punishments (such as non-payment of fines, non-payment of council tax etc.). However, prison is a must for those who are a danger to the public and clearly people who choose to carry a knife to “look big” or for "protection" are a danger to society and thus should be in prison.