The continuing relevance of "Don't Feed the Trolls"

When did "troll" come to mean blunt, vitriolic abuse?

Yes, I know, "language changes and evolves, yada yada yada". I'm curious about this particular usage, which seems to be something that got picked up and amplified by mainstream-media (who seem strikingly ignorant of Internet history), and what to do about the possible loss of the more traditional (and more subtle and rich) meaning of the word among long-time 'Net users.