You all have to check out http://slashdot.org/articles/06/07/03/1213223.shtml
where some guy was advertising a YouTube Killer website in the guise of asn article submit. Turned out he had also advertised it at other sites including digg.
Now think of how massive the slashdot effect is. Add to this the digg traffic and where-ever else he advertised, his server(s) massively got DOS'd:taz:
Now if only he had done the advertising over a few weeks eh...