Personally I don't have an alcohol problem. No really, I don't. I swear. But I DO have a licorice problem, I can't stop once I start even after the point of feeling my stomach cry for mercy. Other people can have just one piece, most don't care for it at all and think its gross, but not me -- I am an insatiable fiend.
We are all different, with different problems. It is important to note that, for the most part, this is a non-confrontational crowd. We would rather get along than not. Which also means sometimes we hide behind policy as opposed to having those hard/difficult/challenging/painful/emotional/scary/etc. individual conversations. Conversations that frankly would be better in the long term for the group AND most certainly benefit that individual. But the key is to approach with a genuine caring.
For example, "Jonathan, can I speak to you in private? About licorice? We bring it to the meetings for everyone, but you don't share and eat it all, then spend the rest of the meeting unproductively in the bathroom. It is setting a bad example for everyone else. Is everything ok? I care about you, we all care about you -- and we want to help."
Call me a big hippy, but hugs sometimes work better than new policies. That being said, there does come a point (
http://en.wikipedia.org/wiki/Dunbar%27s_number) when groups become too large to be maintain "community", at which point, strong leadership/policy or division is a necessary step. There are also real concerns and laws regarding alcohol and minors, don't be negligent, but most importantly use your judgement and discretion.