The law is the law. If you break it, you must pay. When it involves alcohol, I don't think the punishment could ever be too harsh.
I quite agree. The law is in fact law, that's why its called law, and I agree that there must be consequences for breaking the law, though I would be careful about making statements about no punishment too harsh. That sort of mindset is dangerous. Underage drinking is such a common infraction, and by far and away the majority of underage drinkers never get injured, never hurt anyone else, that the punishment in the civilian world is much less than that for DUI with good reason.
See, the thing about no punishment too harsh is that you are saying it about this one instance of illegal activity. But what about all the other illegal activities. Do you ever speed? Or roll through a stop sign? Or gun it to make it through a yellow light? All of those are illegal, but I don't see anyone lining up to hand out the maximum sentence for any of those. The thing is, drinking is a choice, just like breaking traffic laws is a choice. Why must one choice be punished so much more severely than another if no one suffered any harm from it? Maybe the key is better enforcement of the law. If no one gets away with illegal activities, then no one will want to partake in them. But then you have to consider what your society would be, and the answer is not what you want, I guarantee it.
Perhaps the real issue is not actually nineteen or twenty year olds consuming alcohol. Perhaps the real issue is the society we live in that fosters irresponsibility and immaturity. Maybe instead of continuously fighting the symptoms of the disease like they were the disease itself, we should try to cure the actual disease. And that discussion is something that exceeds the scope of this particular forum.
One last thought. If freedom is the ability to choose what you will do, even if its wrong, and justice is the punishment if you choose to do wrong, and perfect justice catches or prevents all wrongdoing, then if you can no longer choose to do wrong without facing punishment, are you still free?