Re: THC, the active ingredient
"...bootleg distillers simply wanted maximum yield, or were totally ignorant of what they were doing."
The same would appear to be true of the people breeding new varieties of cannabis with high THC content, un-balanced by CBD content. THC is a psychotic; CBD an anti-psychotic. When their effects are balanced, cannabis is safe to ingest; when the effect of the THC predominates, it isn't.