Do you ingest caffeine, nicotine, or alcohol on a regular basis? If so, then your crusade against your kids doing any drugs is hypocritical. Also since your son was already an adult at the time, shouldn't he be able to do what he wants as long as he's not living under your roof?
"Also since your son was already an adult at the time, shouldn't he be able to do what he wants as long as he's not living under your roof?"
Yes, he was an adult at the time, but he was living under my roof, and with my rules!