David Frum : Casual use of marijuana should n't be a reason to lock people up . He says there are serious risks to brain development , mental health in using marijuana . Comment: He says too often social rules become so complex many people ca n't navigate them .
David Frum : Casual use of marijuana should n't be a reason to lock people up . He says there are serious risks to brain development , mental health in using marijuana . Frum says it 's better to send simple message that marijuana is illegal . He says too often social rules become so complex many people ca n't navigate them .