I personally don't take drugs, nor do I ever plan to. I have no desire to do so and I can't think of anything that would change my mind and I really couldn't care less about the laws that concern it.
However, I do not feel anyone has the right to tell me or anyone else what they can or can not do based on how healthy or dangerous it may be for us. If I want to juggle chainsaws, that's my choice. If I want to drink bleech, that's my choice. I feel drugs should be the same way...to an extent. Drugs alter the way we act. Period. It is part of the definition of what a drug is. Cafeine alters the normal state of our heart, blood, etc. Alcohol alters coordination, reflexes, etc. I have seen people on drugs, especially acid and marijuana, get super paranoid and do some crazy shit. I was once with a guy who ended up sleeping in the middle of the local wash all night curled up in a ball because he though helicopters were chasing him. There was not a light in the sky: man made, star, or other. All it would take is someone with anger problems, or a violent streek, to just have a bad trip at the wrong time and someone innocent will end up getting seriously hurt. For that reason I believe Marijuana needs to be regulated. Should it be illegal all together, no. Not because I want it to be legal, I just feel no person has the right or power to do such a thing, and if someone does then the balance of power is out of wack.
On the same note though, I feel Alcohol is not regulated enough, or at least that the punishment for it's abuse is not strict enough and not nearly enforced enough. If you can get several DUIs and nothing serious happens to you then something is wrong.
Just my opinion on it.