There's a pretty big precedent for governments intervening in public life to protect people from their own choices and actions. Some people would say that the role of government is to do exactly that.
And do you believe that grouping non-violent, occasional drug users with the violent is a good way of protecting 'people from their own choices and actions'?. Again, what is worse? Smoking a joint or having a criminal record?
Do you believe incarceration and prosecution (with the accompanying social condemnation and stigma) is more helpful than rehab for those who
actually have a problem?
Although I agree that protecting people from making potentially detrimental decisions is a significant role of the government, I don't believe prosecuting and perhaps even incarcerating is the right way to go about it. Why not leave it to education? Not the type most of us have been subjected to in our schooling years, but arguments made with actual evidence instead of mindless propaganda and outright lies
How about a system that treats marijuana the way cigarettes are. Honest campaigns that would discourage people from doing drugs. They should protect us by treating us like responsible adults (those of us that are) instead of nannying us as if we don't know any better. Provide us with the various arguments and allow us to make a decision for ourselves instead of mindlessly locking us up.
I don't choose to avoid heroin or meth because it's illegal, I do so because I know of the risks that are associated with their use. If it were to become legal tomorrow, I highly doubt any of you would go out of your way to try it.
By prosecuting marijuana users, what exactly are you protecting them from? Sure there are risks - many of which can be avoided through proper education - but an overwhelming majority are able to lead perfectly normal lives. Many users would also say that their quality of life has been benefited by their use.
This argument would be much stronger for drugs like LSD, mescaline, ecstasy - where the long term risks can be non-existent if used responsibly. Why exactly are we be 'protected' from using those drugs? Ones that often turn users into pacifists and have minimal adverse health effects?