DH attended USNA when alcohol was banned for all mids, regardless of age. Bars in town were prohibited by a town ordinance from serving mids. Made no difference. It was, of course, obtained and consumed, though consequences were severe.
When I was a BattO at USNA, I asked the Commandant if we could remove car and driving privileges for an offender's entire time at USNA, for any alcohol-related incident, no exception, no restoration. Horrible to contemplate for the two classes without car privileges, horrible for the two classes with. Though he thought that would be a powerful deterrent, he also thought it would create a whole underground of "car cheating" offenses. To his credit, he was consistent and strong about enforcement and consequences of those incidents. Our sponsor mids thought it was pretty devious of me to link one of the most desired privileges to alcohol offenses.
And, thousands of mids and cadets don't do anything stupid with alcohol, or they do it once and scare themselves back into line - but it is the nasty headlines linked to a relatively small group we hear about. There is a lot less of this at the SAs than civilian colleges. Mids and cadets reflect the society they came from. Teaching them responsible behavior and holding them accountable is what they, as officers, will be expected to do with those they lead.