Yep, it was routine in the 60's and 70's, then started tappering off as drug testing and personal standards increased. Almost unheard of these days.
Those few, very few, who do cross that line are quickly found and dealth with. These days they don't get much sympathy from their peers. Honor means a lot more these days.
They were few and far between when I was in also. That is not to say thay you can make a blanket statement that there are no bad apples today using or selling dope.