The agreement (between ICE and BOP) was announced June 7, and marks the first time federal prisons were used to house immigrants in the U.S. on a large scale.

An ICE spokesperson said the agency needed space in prisons “due to the current surge in illegal border crossings and implementation of the U.S. Department of Justice's zero-tolerance policy.”

Prison guards are protesting:

On Friday, members of the local prison guard union representing about 650 employees picketed across the street from the Victorville complex, calling attention to low staffing levels they argue could put guards and inmates in danger.

.... In a June 8 blog post, union president John Kostelnik said the agreement to house 1,000 immigration detainees in Victorville “was not properly planned or processed. None of the agency representatives stood up and informed DOJ or ICE that we were not ready to accept this influx of inmates with the current staffing levels.”

Lack of adequate medical care has been a concern of the union for a while. Here's more on their protest.

In addition, 120 immigrant asylum seekers are being held at the federal prison in Sheridan, OR, including 6 who have been separated from their children. Lawyers report they aren't being allowed to meet with them.

Carissa Cutrell, a spokeswoman for the U.S. Office of Immigration and Customs Enforcement, said generally immigrants apprehended crossing the border illegally are being housed in federal prisons b