Regarding the tragic CO story: Blaming THC for the man's horrendous actions is akin to blaming guns for adam lanza's even more horrendous actions. As stated, and numerous studies have shown, THC has less negative side effects than many, perhaps even most, legal drugs. Hell, it's much easier to OD on aspirin than it is MJ. Caffeine is harder on a person's body than MJ, and caffeine has a rather mild effect on the body. A body experiences withdrawal symptoms from caffeine, none from MJ. MJ is similar to milk, or butter, or pizza for that matter: it's enjoyable to ingest, there are negligible side effects, there are essentially no negative lingering after effects, and no withdrawal symptoms. In fact, I'm pretty sure regular use of butter has more long-term consequences than MJ.
Personally, I don't understand the opposition to MJ. Like anything else, follow the money. Who benefits from having a wildly popular substance banned?