Well it depends what drug they are using. I personally put it into three groups. If its a light drug like alcohol, ciggeretes or marajuanna, then i dont have much of a problem. After this there is "mind expanding drugs", such as lsd and magic mushrooms, which dont have addictive propities, but if taken when depressed can cause serious mental problems later on in life. However I am totally against hard drugs that cause mental dependancy, such as heroin, cocaine, meth, speed etc.
I would say to people who use drugs understand what your getting yourself into, because experimenting can seriously mess up your life.