The Electronic Frontier Foundation (EFF) has filed a lawsuit against the remote testing company Proctorio on behalf of Miami University student Erik Johnson. The lawsuit is intended to “quash a campaign of harassment designed to undermine important concerns” about the company’s remote test-proctoring software, according to the EFF. It’s the latest legal battle for the software company, which has publicly sparred with online critics throughout the last year.

The lawsuit intends to address the company’s behavior toward Johnson in September of last year. After Johnson found out that he’d need to use the software for two of his classes, Johnson dug into the source code of Proctorio’s Chrome extension and made a lengthy Twitter thread criticizing its practices — including links to excerpts of the source code, which he’d posted on Pastebin. Proctorio CEO Mike Olsen sent Johnson a direct message on Twitter requesting that he remove the code from Pastebin, according to screenshots viewed by The Verge. After Johnson refused, Proctorio filed a copyright takedown notice, and three of the tweets were removed. (They were reinstated after TechCrunch reported on the controversy.)

In its lawsuit, the EFF is arguing that Johnson made fair use of Proctorio’s code and that the company’s takedown “interfered with Johnson’s First Amendment right.”

“Copyright holders should be held liable when they falsely accuse their critics of copyright infringement, especially when the goal is plainly to intimidate and undermine them,” said EFF Staff Attorney Cara Gagliano in a statement.

Proctorio is one of the most prominent software platforms that schools use to watch for cheating on remote tests. Its use exploded last year with the rise of remote learning; the platform proctored over 16 million exams. The software records students through their webcams as they work and monitors the position of their heads while they take exams. It flags “suspicious signs” to professors, who can review its recordings. It also enables instructors to track the websites students visit during the exam period and to bar them from functions like copying and pasting text.

Students and instructors around the country have volleyed numerous criticisms against Proctorio, claiming it violates student privacy and has the potential to discriminate against marginalized students. The Electronic Privacy Information Center filed a complaint against the service (and four others) in December, calling it “inherently invasive.” A coalition of US senators, including Sens. Richard Blumenthal (D-CT), Elizabeth Warren (D-MA), and Cory Booker (D-NJ), cited similar concerns about Proctorio in an open letter last year.

Proctorio has engaged critics in court before, although more often as a plaintiff. Last October, the company sued a technology specialist at the University of British Columbia who made a series of tweets criticizing the platform. The thread contained links to unlisted YouTube videos, which Proctorio claimed contained confidential information. The lawsuit drew ire from the global education community: hundreds of university faculty, staff, administrators, and students have signed an open letter in the specialist’s defense, and a GoFundMe for his legal expenses has raised $60,000 from over 700 donors.

“We disagree that sharing confidential information is the same thing as criticism,” Olsen told The Verge at the time. “Posting these kinds of things…it risks students learning how to circumvent the software, and it risks the safety and security of millions of students who use the software.”

Proctorio did not immediately respond to a request for comment on the EFF’s lawsuit.