Do you know how tough it is to convince nicotine addicts to quit smoking? Try it. Militant smokers will always try to convince you that "you're" the cause of all their problems.
Here's what happened when I tried to convince one young lady with "issues" to quit smoking before it's too late. I guess that if you're going to intervene, it's best to have witnesses.
Source: Funny or Die: I Hate You