Google Webmaster Central and the Google Search Quality team have a new ally in the global fight against Web spam, cloaking, paid links, link farms and other non-sanctioned schemes: the Security Group at the University of Cambridge.
Web sites created by Chicago-based Privila were banned by Google earlier this month after Steven Murdoch of University of Cambridge Computer Labs exposed an alleged cloaking scheme by the content network. Steven Murdoch blogged about his findings on March 6th. Two days later Google removed the sites from its index.
It seems that people and spiders were seeing different pages when they visited sites such as soccerlove.com, ammancarpets.com, and canadianbattery.com. People were seeing display ads created by unpaid interns. Google spiders were seeing keyword-rich articles also churned out by unpaid interns. Windows Live and Yahoo! were seeing neither ads nor articles.
Privila already has added the articles back to the sites but the sites are not yet re-indexed.
Murdoch discovered the cloaking after the computer lab where he works received a link exchange spam email from Privila.