John Mark Rozendaal was just trying to play music. On May 29, along with scores of others, Rozendaal responded to calls on social media to gather outside of Delaney Hall, the immigration detention facility in Newark, New Jersey. The privately run U.S. Immigration and Customs Enforcement facility had, in recent weeks, become the site of daily protests, spurred by a detainee hunger strike against alleged ghastly conditions inside. When Rozendaal went to Delaney Hall, he took his cello with him.