The U.S. Immigration and Customs Enforcement agency shut down a hotline for detained immigrants in early August after it was mentioned in several episodes of the Netflix series “Orange Is the New Black.”

The National Immigration Detention Hotline, which ICE had provided as a pro bono telephone extension, was run by advocacy group Freedom for Immigrants to allow ICE detainees to access to legal aid, contact their loved ones, and confidentially report abuses at the holding facilities.

The nonprofit’s executive director, Christina Fialho, and its hotline director, Cynthia Galaz, sent ICE a cease and desist letter last week blasting the agency’s “impermissible retaliation to the organization’s First Amendment-protected expression.”

“The hotline’s termination also creates the clear appearance ICE is attempting to silence critics and limit the public’s awareness of alleged abusive conditions in immigration detention,” they wrote.

“The termination of Freedom for Immigrants’ pro bono line violates the First

Amendment’s prohibitions against discrimination for protected speech,” Fialho and Galaz wrote near the end of the letter. “The line’s termination, moreover, undermines trust and accountability of government institutions, dissuades public service by community organizations, and further isolates vulnerable detained individuals.”

The letter also pointed out the irony of ICE’s actions, given that one of the show’s characters warns another other, “You gotta be careful though. Apparently as soon as Big Brother figures out you’re using the hotline, they shut it down.”

ICE denied that the termination was connected to the show in a statement sent to HuffPost on Monday, claiming that Freedom for Immigrants had “engaged in prohibited conduct” by operating call forwarding and three-way calls.