I didn't see or hear anything about that, and I mix with a wide cross-section of passengers.
On last March's cruise one person was taken off in handcuffs cuz they had been smoking dope in their room a lot, and someone in a room nearby didn't like it, but rather than asking them to stop cuz the smell bothered them, they narced on them- so the story goes.
I personally have never tried drugs, but if you indulge in them in the Carribean, smoke them where you get them. and do NOT think that you will sneak by US customs with a stash you are taking home. Often they have the canine patrol checking not only the passengers, but also the luggage! The same goes for any plant material etc.
be smart, and be safe!