In Tucson, Arizona, immigrant rights advocates disrupted proceedings at a federal courthouse Friday when they blocked the entrance and locked themselves to the wheels of two buses carrying undocumented people bound for the court under a controversial program known as Operation Streamline. The Bush-era program sees immigrants accused of crossing the border without authorization sentenced by the dozens to prison terms of up to six months before they are deported. Protesters say the process funnels immigrants into the for-profit prison system. Today immigrant advocates are expected to march on the headquarters of Immigration and Customs Enforcement in Phoenix as part of a call to halt the unprecedented number of deportations under President Obama.