President Donald Trump signed an executive order Monday revoking the security clearance of 51 former intelligence officials who signed a 2020 letter arguing that emails from a laptop belonging to Hunter Biden carried “all the classic earmarks of a Russian information operation.”

Many of the 51 former officials are long retired and no longer hold active clearances — meaning that the move may have limited practical impact on their careers — but the order nevertheless suggests that Trump intends to act on threats he’s made to penalize national security and intelligence professionals whom he deems to be his enemies.

“They should be prosecuted for what they did,” Trump said of the 51 former officials who signed the letter, at a campaign rally in June.

The letter was signed by a number of top former officials from both the Obama and Bush administrations, including former director of national intelligence Jim Clapper, former CIA director John Brennan and former acting CIA directors John McLaughlin and Michael Morell.

In the four years since the letter was written, its authors have become a key target for Republican lawmakers and Trump’s allies. GOP lawmakers on Capitol Hill have made the origins of the letter a key focus point, calling up a number of signatories to testify behind closed doors and issuing several reports on the matter.

The letter almost immediately became a flashpoint in the partisan wrangling over the laptop itself, which contained sexually explicit videos of the former president’s son with women, as well as photos of him doing drugs in hotel rooms, many of which have since been published by right-wing media outlets.

When the existence of the laptop and its contents first became public through reporting by the New York Post, many mainstream media outlets questioned its authenticity and social media companies moved to restrict the ability of users to share the Post’s coverage, following questions about whether it could have been part of a foreign influence campaign — a skeptical approach that was in part bolstered by concerns raised in the letter, which were not ultimately borne out.

“We want to emphasize that we do not know if the emails… are genuine or not and that we do not have evidence of Russian involvement — just that our experience makes us deeply suspicious that the Russian government played a significant role in this case,” the former officials wrote in 2020. “If we are right, this is Russia trying to influence how Americans vote in this election, and we believe strongly that Americans need to be aware of this.”

Since then, the laptop and its contents have been recognized as legitimate. It played a role in the younger Biden’s prosecution on felony drug charges, with special counsel David Weiss calling questions about the laptop’s authenticity a “conspiracy theory.”

Republicans have argued that the letter was evidence of a deep-state collusion between the CIA and the Biden campaign to cover up other materials on the laptop that they believe show improper foreign business dealings by the Biden family. There was coordination between the former officials who wrote and signed onto the letter and the Biden campaign, a Republican congressional investigation has documented, and Joe Biden, then a candidate for the presidency, cited the letter during a presidential debate at the time.

But the claims that materials on the laptop prove foreign corruption have not stood up to vetting, even as the authenticity of the device and some of the embarrassing material documenting the younger Biden’s drug use and sexual activity have been confirmed by multiple press outlets.

And all 51 signatories were private citizens at the time they wrote the letter, although a handful held contracts with the CIA at the time, the Republican congressional investigation later found. At least one of those contracts was an unpaid position.

Some did not hold clearances when the letter was written or no longer maintain one; Clapper, for example, does not currently have an active clearance.

“It would be contrary to decades of national security norms to suspend the security clearances of individuals who did nothing other than, as private citizens, exercise their protected First Amendment rights,” said Mark Zaid, an attorney who represents a number of the signatories. “Such an action would be unprecedented and undeserved, especially given many of the signatories spent their entire careers serving apolitically to protect the American people.”

Hunter Biden’s lawyers have said the files were manipulated and even sued a computer repair shop owner who publicly released the material.

Biden dropped off the laptop at a Delaware repair shop in April of 2019. His lawyers said in a court filing that the shop owner admitted in his memoir that he “began accessing sensitive, private material in the data” right away, and continued to potentially tamper with the data throughout the five months before the FBI seized the device.