The Great Recession was characterized by a historic and gigantic wave of foreclosures all around the country. Left and right, people were being removed from their homes. But because of the explosion of mortgage securitization -- the slicing and dicing of financial assets that got Wall Street into so much trouble -- there was often a failure to do the proper paperwork required for such evictions. This week on Odd Lots, we talk to David Dayen, the author of the new book Chain of Title, about a group of activists in Florida who self-taught themselves to become experts on securitization and foreclosure law in order to fight back in court against what they argued was fraudulent activity.