“Indefensible: A Decade of Mass Incarceration of Migrants Prosecuted for Crossing the Border,” documents the history and failures of migrant criminalization through the voices of those most impacted—including migrants and their families; and those with a firsthand view into the system— including judges, defenders, and human rights advocates. In 2015, improper entry and re-entry accounted for nearly half (49%) of all federal prosecutions. The report details the origin and evolution of Operation Streamline and the related expanded felony immigration prosecutions, that added a criminal process to a what was previously usually civil removal process, at a cost estimated at $7 billion dollars in incarceration costs alone since 2005. The report connects the expanded migrant prosecutions to mass incarceration and overcrowding in the federal prison system, to the benefit of private prison companies. Despite costs to taxpayers and human lives, there is no evidence to suggest that incarceration deters migration, which is more strongly motivated by economic circumstances and family responsibilities.