Is it not obvious that the best way to protect users from the unknown dangers of synthetic cannabis is to re-legalize and regulate the real thing ("Ending the scourge of fake marijuana in Maryland," Oct. 8)?  It has been used for thousands of years with no documented deaths and is widely known to be one of the safest mind altering substances.  Once again prohibition is the cause of death, disease and increased danger to drug users.   Dave Lane, Santa Cruz,Calif.