None of those links support the assertion that the prisons are "filled with law abiding citizens whose crimes consist merely of possessing illegal narcotics for personal use", in America, (stats useless when discussing Canada), let alone Canada.
The majority of people involved in importing/exporting, manufacturing, and distribution of illegal narcotics are in fact criminals for the most part, and they are the ones locked up under the "Drugs" classification, not the average guy who consumes some.