Definitely an interesting topic!
I am for at the very least the decriminalisation of cannabis. My view is similar to PhoenixxFire, addiction (to any drug) should be treated as an illness, rather than a crime (those who sell or distribute illegal drugs however...). If it came to a vote, I believe that I would vote in favour of legalisation of cannabis, even for recreational purposes. This is mainly because marijuana is less dangerous than other legal substances - namely alcohol. It's not only less likely to kill you (very difficult to overdose on weed unless you have allergies or a pre-existing condition whose symptoms can be exacerbated by cannabis), but you're also less likely to hurt others (I've personally never heard of a pot-head going out and king hitting someone, however drunk people are implicated in this behaviour all the time).
Definitely should be regulated in some way, but imo thats another reason why legalising it is a good thing - it can be regulated. Whereas right now the government has little control over who has access, how much they have access to, and whether or not the weed is (unsuspectingly) laced with other substances, if it was to be made legal and people could purchase it over the counter that actually makes it overall safer for the community (even if there are more people who recreationally smoke weed, in the same way that people recreationally consume other drugs like alcohol and tabacco).
At the same time though - don't think is should be encouraged. People should still know that any drug is not "safe" to use, and that it can have negative consequences on physical and mental health. Though it may be less likely than with other, stronger drugs, you can still become addicted to cannabis, and when it gets to that point, avenues for help must be open an available.