To some, it appears that Google has painted itself into a corner with its reliance on linking for its ranking algorithm. The lines between legitimate SEO, paid links, and Google bombs are becoming increasingly blurred.
One highly-charged example is the case of Jew Watch News, an anti-semitic hate site that managed to get top ranking for the query "Jew." Several Jewish and anti-defamation groups joined together in a coordinated Google bombing campaign to push that result down in the SERPs, and the results of that bomb can still be seen today.
In today's SearchDay, "Google Bombs, Jew Watch News & the Hypocritical Linking Universe," Marty Weintraub looks at that Google bomb, and tries to find where a Google bomb meets SEO, and where paid links fit into the picture.