On one of my Disney cruises, my DD's witnessed a group of teens partaking of illegal drugs on board the ship. They immediately left the group and returned to our stateroom soon after to let me know of what they saw. Since we were disembarking the next morning, I just advised that they call it a night at that point, which they did.
So the next morning while eating breakfast in Lumiere's we saw several customs agents rushing through the corridor with apparently a drug sniffing dog. We do not know the outcome, but were told that they had found the individuals that had the drugs on board ship.
Not a good idea to take such items on board, especially when you are leaving and/or entering the country and subject to U.S. Customs laws too.