I authored some work recently in which we identify an instance of potential market manipulation. Here's the page on NECSI's website. Here are reddit posts about it in economics, politics, math, finance, and occupywallstreet. Here's an HN post about it. It was covered by BoingBoing, PhysOrg, ScienceNews, Technology Review, ZeroHedge, Naked Capitalism, and others.
Market manipulation in the financial crisis
December 20, 2011