In 2009, the US Immigration and Customs Enforcement agency (ICE) held between 380,000 and 442,000 people in some 300 US detention facilities, at an annual cost of $1.7 billion. These people are not imprisoned as punishment for criminal offenses, but rather are detained for civil immigration violations. Many will be deprived of their liberty for months, some for years. And many are being held unnecessarily, at great cost to themselves, their families, and US taxpayers. At least since 1996, ICE has enjoyed relatively unchecked powers to sweep non-citizens into detention. This report is one of a series looking at flaws in current immigration policy that can be remedied through specific administrative and legislative actions.