Most of the research that has been done with smoked cannabis have the highest THC at 8%. Are you saying all these researchers were clueless as to the actual potency of the THC? I’m saying that those were degraded samples and not representative of the average in potency. You said that “the potency of THC in currently available marijuana has quadrupled since the mid-1990s.” I’m saying that it hasn’t quadrupled. The focus on increased potency is a red herring anyway. Even low-potency cannabis can easily be ‘screened’ to separate the resin glands from the rest of the plant matter, resulting in a high-potency loose form of hash. Further, smoked cannabis has a point of diminishing returns that is quickly reached; smoking a given variety beyond that point will not get a person much higher. I reject the notion that cannabis causes violence. For those who didn’t read the article, it actually tries to blame the events of September 11, 2001 on marijuana. Good grief!