The Sorrows of Young Werther. In 1774, Johann Wolfgang von Goethe wrote a book about a love-lorn man who kills himself. Such was the power of the book that supposedly over 2,000 readers committed suicide after reading it. The book was banned, and even now, clusters of copycat suicides are attributed to the
Werther Effect.
This may be the most dangerous link I've ever posted, but you can read it (in the English translation)
here.