There's a handy list of the harms of prohibition up at Helen Hughes's' 'Speakeasy' newsletter site. If the Greens hadn't lost their freedom mojo (did they ever really have it?) they might themselves have spent some time at their weekend conference pointing out some of these iniquities, or trumpeting the new US report which calculates the cost of prohibition -- it's not cheap.
Sadly, their conference has ended instead with little of substance beyond name-calling (Peters as Hitler and a "snake oil merchant" -- one of which is at least correct -- Brash as sexist and racist), context-free scare-mongering (somebody has stolen all the clean water and it's all your fault), and a call for more theft in order to buy the votes of students.
So, nothing really new then, apart from the name-calling from Rod and Jeanette.