The 1960's spawned a drug craze that ballooned until drugs too, were banned. Once the laws banning sale and use of drugs went into effect, drug use in the US ceased overnight.
Gun deaths in major US cities too have been stopped. New York city and Washington, DC are two determined sticklers where gun ownership has been curtailed. Both cities saw a resurgence of comity and serenity when guns were banned and the deaths stopped.
Yes, ban world trafficking in caviar. Six billion people will agree, voluntarily to comply. The fish will be saved because no one will buy another ounce of caviar.
Actually, prohibition worked. It limited consumption of alcohol by 60%.
It did give rise to a black market and created a host of other crimes in the process, but it did limit the consumption of alcohol. I don't know how this misinformation keeps being spread, but look it up. Consumption went down.