One of his most dastardly villains ever.
Yup. In 1971 the U.S. government (through the Department of Health, Education, and Welfare) actually asked Stan Lee to include an anti-drug arc in the incredibly popular Spider-Man comics. Which means Peter Parker is exactly as strait edge as you think he is. The success of the message is dubious, but it is kind of funny to look at now (via).
Harry Osborne wasn't too lucky.
He was addicted to "relaxers", which seemed to have a psychedelic effect but were also making him lose his mind. He was sick enough that his father Norman was actually deterred from getting revenge on Spider-Man. The Comics Code was also altered after Spider Man #98 was released (since it hadn't addressed drug use before); after that drugs were only allowed to be depicted in a negative light. Way to ruin it for everyone Spider-Man.
Then there's this dramatic showdown.
Because a scene with Jonas wouldn't be complete without an unnecessary argument.
All joking aside though, substance abuse is a real problem. And while the comic definitely lacked a lot of the nuance it probably would have needed to get a real message across, it was a pretty heroic thing to do.
That's right Troy.