Marijuana is harmful in the same way smoking is harmful - smoking anything (inhalation of damaging substances to the membrane of your lungs) is dangerous in general. Now, anything not done in moderation is also equally as dangerous. That being said, I've seen far more horrible things in this life arise from drinking and not arise from smoking marijuana. I've seen more people get hurt, do something stupid, or crash a car because drinking. I've never been with/seen anyone who's crashed a car while stoned, or wanted to start a fight with their ex girlfriend. (interesting night, to say the least). I've only ever wanted to relax, mellow out. Is it SAFER? A drug is a drug. Like xTinx said, it's really in the intention of the user/person using.