Originally Published: 09 AUG 22 16:19 ET

Updated: 10 AUG 22 15:12 ET

By Donie O'Sullivan, CNN

(CNN) -- "Lock and load," was one of the top comments on an online forum dedicated to former President Donald Trump on Monday night, soon after it emerged his Florida Mar-a-Lago resort had been searched by the FBI.

Other posts were more explicit, "I'm just going to say it. [Attorney General Merrick] Garland needs to be assassinated. Simple as that." Another user posted, "kill all feds."

Users also encouraged others to post the address of the magistrate judge they believe signed off on the search warrant. "I see a rope around his neck," a comment under a picture of the judge read.

On the same forum, researchers previously found talk of violence and discussion on how to attack police officers in the weeks leading up to the January 6, 2021, attack.

Amid the users on the forum Monday night was a convicted US Capitol rioter.

One reply to the top-rated "lock and load" post came from an account with the username bananaguard62 and asked "Are we not in a cold civil war at this point?"

By combing through bananaguard62's posts, Advance Democracy, a non-partisan, non-profit organization that conducts public-interest investigations, identified Tyler Welsh Slaeker as running the account.

Slaeker was charged by the Justice Department last summer in connection with the January 6 attack. Slaeker's in-laws tipped off the FBI about his presence at the Capitol, according to court filings, making him one of the many January 6 rioters who were turned in by family members.

He was initially charged with four nonviolent misdemeanors, and pleaded guilty in June to one count of entering a restricted building. His sentencing is scheduled for November.

NBC News was first to report Advance Democracy's findings on Slaeker. His attorney did not immediately respond to a request for comment.

It can be difficult to distinguish between empty and serious threats of violence online, but it cannot be ignored, said Daniel J. Jones, a former US Senate investigator who led the investigation into the CIA's use of torture and now runs Advance Democracy, a non-partisan, non-profit organization that conducts public-interest investigations.

"We are seeing conspiratorial rhetoric from elected officials, political leaders, and political entertainers that is fueling calls for real-world violence," Jones said. "The conspiratorial and divisive rhetoric -- from elected officials and others who should know better -- is continuing to undermine our institutions and democracy at an alarming rate."

A congressional security official told CNN shortly after news of the search warrant broke Monday night, US Capitol Police began discussions about monitoring and planning for potential violent rhetoric.

Of particular concern is the possibility violence could be directed at members of Congress or other federal law enforcement, the security official said.

The Capitol Police declined to comment on security plans.

One post CNN found called for violence against FBI agents. The FBI declined to comment on the post or wider security concerns due to violent rhetoric.

After the January 6 attack, alternative social media platforms became more popular among Trump supporters after companies like Facebook and Twitter banned Trump and some other prominent figures who spread election conspiracy theories.

Those platforms, like Trump's own Truth Social site, tout themselves as bastions of free speech, with looser rules and moderation. But that can result in the proliferation of violent rhetoric. CNN reported in June how threats against members of the January 6 House select committee circulated on those platforms.

But talk of violence isn't exclusive to the more fringe platforms.

There was a surge in tweets Monday mentioning "civil war" -- at some points more than one tweet a second, according to a CNN review of data from Dataminr, a service that tracks Twitter activity. While some mentions of "civil war" came from Trump critics expressing fear what his supporters might do -- one researcher posted multiple screenshots of Twitter accounts outright calling for civil war.

Jones, whose group Advance Democracy has been tracking online threats since the FBI raid on Monday, said political leaders posting on their main social media accounts are stoking more violent rhetoric.

"The attack on the Capitol on January 6th showed that we can't ignore calls for political violence online -- no matter how fringe the theories are behind those calls for violence," Jones said.

Magistrate judge's bio removed from court website

The biography of a federal magistrate judge in Florida, along with their contact information and office address, were removed from the court's website amid the right-wing backlash to the FBI search.

The magistrate judge has been identified by some media outlets as the judge who approved the FBI warrant. CNN has not independently confirmed that this is the judge in question and is not naming him at this time.

Records reviewed by CNN show the webpage with the judge's information was removed from the official website for the US District Court for the Southern District of Florida sometime between Tuesday evening and Wednesday morning.

Reached for comment Tuesday, officials from the court didn't say why the judge's webpage was removed. CNN has requested comment from the FBI, the Palm Beach Gardens Police Department and the US Marshals Service.

On Tuesday, on pro-Trump social media sites, there were calls for the publication of the judge's home address, according to Ben Decker, the CEO of Memetica, a threat analysis company.

Decker has seen a "massive surge" in threats targeting the judge since Monday, including, he told CNN, on message boards "that played a notable role in the lead-up to January 6."

In the federal court system, magistrate judges often handle procedural matters before the cases are assigned to a district judge, which is a much more prominent position and requires a presidential appointment and Senate confirmation.

Magistrate judges differ from the US district judges who are appointed by presidents and confirmed by the Senate. Magistrate judges handle tasks like authorizing search warrants and conducting the preliminary proceedings in a criminal case, though they don't have all the powers as a district judge.

This story has been updated with additional details.