Not to mention it grows itself (no "corp. farming" needed) & the rest of the plant is industrially useful (18,000 uses & counting).
well we certinly found out that one use of marijauna was to supply a way for governments to excercise control over the populus. i.e. the war on drugs.
It used to be illegal "not" to grow it (tax payment for crown to rig up the ships).