Why do people not have on off button when drinking in public? Why do people lose control when drinking in public? Why do people often become belligerent and aggressive when drinking in public? Allied to trying to answer those questions, consider the reluctance of the Lord Advocate some years ago to proceed with cases where the sole charge was the common law crime of breach of the peace. Along with this, consider the diminution over time of the power of the police to arrest without warrant a person who has been accused of having committed a crime shortly before, and detain them in custody until appearance at court.