This is not a surprise to anyone who glances at even moderately extreme sites like The Donald. I can't begin to imagine how bad it is on the dark sites like Rumble and Telegram. Via CNN:

The FBI and Department of Homeland Security are concerned that “election-related grievances,” such as a belief in voter fraud, could motivate domestic extremists to engage in violence in the weeks before and after the November election, as it did during the January 6, 2021, attack on the US Capitol, according to a new intelligence bulletin from the agencies.

Domestic violent extremists [DVEs] “continue to create, exploit, and promote narratives about the election process or legal decisions involving political figures, and we are concerned that these grievances could motivate some DVEs to engage in violence, as we saw during the 2020 election cycle,” the FBI and DHS said in the bulletin sent to state and local officials and private executives, which CNN obtained.

Extremists with such grievances, which could include “anger toward perceived political adversaries,” pose the most likely threat of extremist violence to election-related targets in the final weeks of the 2024 election cycle, through at least the inauguration in January, the federal assessment says.