at the time, there were no recorded (acknowledged) incidents using the 'net as medium. then, in september 2000 the Orange Co Register was defaced with a subversion of information attack. The content of the Web site was altered slightly so that it wasn't readily apparent that the stories weren't real. <http://www.thestandard.com/article/display/0,1151,19219,00.html>
this kind of attack has also been called a "semantic attack" among information warfare folks. (as opposed to syntactic attacks which attack the logic of a computer or network of computer, as a logic bomb or virus does; or physical attacks against the actual hardware, power grid, etc). in the above case, bill gates' name was replaced for the names of the accused hackers in three news stories. nothing else about the site was changed and it was hard to tell is was a web site defacement, save for some all-caps and bizarre msg toward the end. (like the new yorker spoof doug forwarded too which was hard to tell if it was a spoof were it not the fake adverts).
another form of a semantic attack is Emulex and other similar incidents: information is circulated via the net, pumping up a stocks' price and, in this case, a false press release exacerbated what is only just a stepped up, hyper-version of what happens all the time with stocks.
which is why i write: are there preInternet precursors to Emulex?
kelley