A legal defense fund for the journalist Barrett Brown is suing the Justice Department, accusing Brown’s prosecutors of abusing their power by monitoring anonymous political contributions to the fund.

After Brown was arrested in 2012 for work related to hacks on intelligence contractors, a San Francisco-based systems administrator named Kevin Gallagher launched the website Free Barrett Brown, which crowdfunded tens of thousands of dollars for Brown’s legal defense.

Free Barrett Brown is now defunct, because Brown was released to a halfway house in November. But the group on Tuesday challenged the legality of a 2013 subpoena that it says violates their donors’ First Amendment rights to anonymously support political causes. The subpoena was sent to the host of the crowdfunded legal defense fund, directing it to send “any and all information” pertaining to the legal defense fund to the FBI.

“The subpoena claimed that the information it requested would be used at the trial of the jailed journalist. However, the identities of, and the amounts donated by, the journalist’s supporters are completely irrelevant to the charges levied against the journalist,” the group says in its filing. Indeed, no such information was presented at trial. The real purpose was to “unlawfully surveil the donors in violation of the First Amendment,” the suit says.

“Learning that these records were sought and obtained was highly unsettling,” said Kevin Gallagher, Free Barrett Brown’s former director said in a statement. “If we don’t send a message to the government that it’s not okay to target private legal defense efforts, then they will continue to get away with these sort of things.”

“The donations were acts of political expression, showing the donors’ frustrations with what they perceived to be government bullying and prosecutorial overreach,” the lawsuit said. “Donations made in support of litigation are protected by the First Amendment. The donors violated no law by sending money to support Mr. Brown’s legal defense, and instead were exercising their constitutionally protected rights.”

Brown was arrested in 2012 for his reporting related to two major hacks against intelligence contractors by a group sympathetic to the hacker-activist collective Anonymous. One — against the firm HBGary Federal — revealed a plot to target and smear liberal reporters, labor unions, and WikiLeaks defenders.

Federal prosecutors initially saddled Brown with fraud charges, which could have given him a 100-year sentence, all because he shared a link to documents taken in the hacks that contained credit card numbers. Those charges were eventually dropped, but Brown was sentenced to five years in prison, mostly due to his threatening an FBI agent in videos posted on YouTube.

In 2016, Brown won a National Magazine Award for his column in The Intercept, the Barrett Brown Review of Arts and Letters and Prison.