RICHMOND, Va. (CN) – A cadre of civil liberties groups filed an amicus brief in Devin Nunes’ defamation lawsuit against Twitter, claiming the Republican congressman’s attempt to unmask users behind parody accounts could lead to a First Amendment violation.

In the 39-page brief filed late Monday in the Circuit Circuit of Henrico County, Virginia, attorneys with Public Citizen Litigation Group and the American Civil Liberties Union argued that forcing Twitter to reveal the people behind an account called Devin Nunes’ Cow and a since-deleted account claiming to be the lawmaker’s mother would run afoul of the right to free speech.

“Full First Amendment protection applies to communications on the internet, and longstanding precedent recognizes that speakers have a First Amendment right to communicate anonymously, so long as they do not violate the law in doing so,” Paul Alan Levy of Public Citizen wrote. “Thus, when a complaint is brought against an anonymous speaker, courts must balance the right to obtain redress from the alleged perpetrators of civil wrongs against the right to anonymity of those who have done no wrong.”

Levy wrote the brief to address a motion to quash a subpoena filed by the Richmond-based Hawkins Law Firm, which Nunes claims handled money from a Go Fund Me campaign aiming to raise legal funds for the parody Twitter accounts. Nunes’ motion sought to compel the law firm to reveal the users’ identities, but Levy said that in addition to the First Amendment issues, the subpoena did not include evidence supporting the release of the identifying information.

“Requiring actual evidence to enforce a subpoena is particularly appropriate where the relief itself may undermine, and thus violate, the defendant’s First Amendment right to speak anonymously,” Levy wrote.

Nunes first filed the $250 million complaint in March, alleging the social media giant is “knowingly hosting and monetizing content that is clearly abusive, hateful and defamatory.”

The congressman’s claims raised eyebrows because it was filed in a suburban Richmond court, far from his congressional district and Twitter’s headquarters, both located in California.

While Nunes and his lawyer, Charlottesville-based Attorney Stephen Biss, have refused to comment on the choice of venue for the filing, Levy and others have suspected a Virginia state court was chosen because of the state’s looser anti-SLAPP, or strategic lawsuit against public participation, laws. That makes it more costly to fight against defamation claims.

But Henrico County Judge John Marshall sided with Nunes in an October ruling, saying Twitter has reach in Virginia and another defendant in the case, Republican strategist Liz Mair, sent some of the tweets at issue from within the state.

Legislative efforts to strengthen Virginia’s anti-SLAPP laws have been rumored for the upcoming 2020 session and could find support from the new Democratic majority.