Ever browsed to the very last page of Google for any set of search results? This one is for "advertising". Even though GOOG says it has about half a billion pages about advertising, it only displays the first 1000 results (or 100 pages including duplicates), but it still feels a bit like standing at the edge of the universe and staring into the eternal darkness.
Which brings us to a recent Forbes article The Saboteurs of Search about "negative search engine optimization", a handy approach for relegating critics or competitors to where the search sun doesn't shine. In the toolbox: Google bowling (creating spam links to the target site), tattling (similar, only involves purchasing links), insulation (creating better-optimized content that would float nearer the top), filing DMCA complaints, creating sites with content duplicating the original, denial of service attacks (not sure why list it here), and click fraud.