http://nakedsecurity.sophos.com/2012/10/05/bing-image-blackhat-seo-poisoning/
"Earlier this week I was asked to look at how search engine poisoning was being used to drive web traffic to payday loan sites.It turned out that compromised websites were being abused, in order to attract search engine queries, and drive more traffic to the target site(s).
Regular readers will recognise this technique - it is exactly what we have seen being used to drive traffic to malicious websites for several years now."
