David Nutt
Notes
David Nutt (born 1951), English neuropsychopharmacologist at Imperial College. Chaired the UK Advisory Council on the Misuse of Drugs until he was dismissed in 2009 by the Home Secretary for stating publicly that alcohol and tobacco are more harmful than cannabis, ecstasy, and LSD, which is what the evidence says. Drugs Without the Hot Air (2012) is the clearest account of drug harms for a general reader. The dismissal is the standard example of a government preferring policy to evidence.
Wikipedia: https://en.wikipedia.org/wiki/David_Nutt