God. All those anti-drugs people... I'm amazed at the blind prejudice and sheer venom. The urge to get good and wasted has been with us for tens of thousands of years at the very least. It's not going away anytime soon, and this wave of disapproval will come and go.
Sucking back beers all weekend. Smoking cigarettes or vaping. Doing bongs. Taking anti-depressants because life is sad and meaningless and we need to remain productive economic units. etc etc.
I always like the "drugs screwed up my/friend/kid/wife's life". No they didn't. They screwed up their life. drugs were the vehicle is all. There always has to be something to blame apart from the one who is to blame.To extend the metaphor, drugs can take you to work, or on a long country drive or you can keep the pedal to the floor for thrills and risk ending up on a lamppost. Can't blame the car.
As to dealers, if one is not opposed to people taking drugs, then how can one be opposed to someone supplying them? Set aside adulteration/ leg breaking etc. That is just people being bad and doing unconscionable things. We don't hang people that work in pubs do we? If they started adding bleach to the beer, we wouldn't say publicans are bad or all beer is poison; just that that was a bad pub/beer.
Bear in mind there are countries like Portugal who have legalised pretty well everything and has their society fallen apart? Nopes.
I think there is an argument for not operating machinery or the like when on certain drugs/medications, but what of it? That's safety is all and it depends on how far you want to take it. I bet Gillard made some decisions on the SSRI's or beta blockers (or whatever she was on that gave her such a flat affect) that she would not have made when not on them. I think the abnegation of responsibility when under the influence is bs. I don't accept the "I was wasted" argument.
TL;DR: If you do bad things you should get in trouble. If you do bad things on drugs, you should still get in trouble. If you do drugs and do not do bad things, then it's noone's business IMHO.
As to Ms. Corby, I believe she has been in there long enough, but I believe that of her cellmates too. I do not think we will ever know for sure if she did it or not. I think she did, but what do I really know?