Well the true origin goes even further back than that. Trolling means to patrol or patrolling which is to walk slowly and survey. That would explain why the term is used in fishing. Also it explains why supernatural trolls were given the name, because they were said to walk slowly or clumsily.
What I was referring to though was the identity deception being spoken about, not the etymology of the word itself. One of the earliest cases of being an internet troll can be traced to the early eighties. Check out the story of Alex and Joan, the original internet troll.
http://meatballwiki.org/wiki/AlexAndJoan
That's ****** up....