Environmental activist Daniel McGowan has filed a lawsuit against the U.S. Bureau of Prisons for jailing him in solitary confinement after he wrote an article about his earlier imprisonment. McGowan spent more than five years in prison for arson as a member of the Earth Liberation Front. For part of his term, he was held in the prison’s highly restrictive Communications Management Unit, or CMU. After his release to a halfway house in 2012, McGowan wrote an article for The Huffington Post about how documents proved he was held in the CMU in retaliation for his political speech. Three days after the article came out, McGowan was again taken into custody and told he would be returned to a CMU. He was released the next day after federal authorities were notified they had arrested him under a regulation declared unconstitutional. McGowan’s attorney told The Huffington Post, “Communication management units are wrong now, they were wrong then, and trying to tell that to the world should not get you thrown back in prison.”