or for plausible deniability: if LSD is kept illegal (to insure the majority doesn't use it, and doesn't sympathize with those who do), while kept available (to insure there will be enough people who use it recreationally), then the large but relatively smaller latter group can be used to draw test subjects from, and if things go sideways, you have a documented history of voluntary drug abuse events of an individual to point to in order to obscure the involuntary drug experimentation event that went sideways.