I've heard of this before too and its a shame it never gets out to the mainstream media but this..

"In 1983 the Reagan/Bush Administration tried to persuade American
universities and researchers to destroy all 1966-76 cannabis research work,
including compendiums in libraries, reports Jack Herer, who states, "We know
that large amounts of information have since disappeared."

sounds like book burning. That hasn't gone on for a while, I hoped that had been left behind us.