Since U.S. President Donald Trump took office in January, the judicial branch has served as something of a firewall against some of his attempts to subvert congressional authority and undermine long-established constitutional law, with federal judges blocking his orders to end birthright citizenship, cut foreign aid funding, and other parts of his agenda.

But as the rulings have been met with relief from rights advocates, the judges who have handed down the decisions have faced mounting threats from anonymous people or groups who appear to support Trump—with remarks from Republican lawmakers and the president himself only emboldening the threats of violence.

As The New York Times reported Wednesday, judges who have ruled against the administration’s policies in recent weeks have received “bomb threats, anonymous calls to dispatch police SWAT teams to home addresses, even the delivery of pizzas, a seemingly innocuous prank” which is meant to convey an ominous message, suggested one judge who was targeted.

“They know where you and your family members live,” said the judge, who is overseeing a case pertaining to the Trump administration.

On Tuesday, Trump called for the impeachment of Chief Judge James Boasberg of the U.S. District Court for the District of Columbia and derided him as a “radical left lunatic” after Boasberg barred the administration from deporting Venezuelan immigrants to El Salvador under the 1798 Alien Enemies Act. His comments followed those of Rep. Brandon Gill (R-Texas), who pledged to file articles of impeachment against the “activist” judge.

Trump’s remarks prompted U.S. Supreme Court Chief Justice John Roberts to warn that “impeachment is not an appropriate response to disagreement concerning a judicial decision,” advising those who oppose federal rulings to do so via “the normal appellate review process.”

Roberts’ warning didn’t stop anonymous critics on social media from demanding that Boasberg be sent to Guantánamo Bay “for 20 years” and calling him a “terrorist-loving judge.”

Far-right conspiracy theorist Laura Loomer, who traveled with Trump during his campaign last year, told her 1.5 million social media followers that the judge’s family “is a national security threat.”

U.S. Sen. Sheldon Whitehouse (D-R.I.) on Thursday likened the response of Trump and the MAGA movement to the judiciary to setting loose “flying monkeys to intimidate judges and their families.”

Supreme Court Justice Amy Coney Barrett, one of the court’s right-wing judges who was appointed by Trump, broke with the other conservative justices earlier this month when she ruled against the president’s freeze on foreign aid—prompting allies of the president to deride Coney Barrett as a “closet Democrat” and a “DEI hire,” referring to diversity, equity, and inclusion initiatives that Trump has pushed to end.

Days after the ruling, Coney Barrett’s sister received a threat—which turned out to be false—that there was a pipe bomb in her mailbox.

Judge John C. Coughenour of the U.S. District Court for the Western District of Washington also reported that he had been targeted by a “swatting” attack, in which a false tip was sent to local law enforcement, prompting officers to show up at the judge’s home expecting to find an armed intruder. The attack followed Coughenour’s ruling that blocked Trump’s order attempting to abolish birthright citizenship.

Reutersreported earlier this this month that “U.S. marshals have warned judges of unusually high threat levels.”

“Security has been bolstered for some judges assigned cases over Trump administration initiatives,” the outlet reported.

The government watchdog Public Citizen said the threats against judges who rule against Trump is a “red flag.”

“This presidency is starting to look a lot like a dictatorship,” said the group.

Maggie Jo Buchanan, interim executive director of the court reform advocacy group Demand Justice, said that “judges should not face threats of impeachment, violence, or worse, simply for doing their jobs and upholding their oaths to the rule of law and Constitution.”

“Criticism and public discourse around rulings is a part of our democracy,” said Buchanan. “Threats and intimidation are not.”