Re your statement: “Black people engaging in self-defense are often seen as violent.”
True, because racists are bullies and do not like anyone who fights back
Re Hoover’s statement that the Black Panther Party for Self-Defense was "the greatest threat to the internal security of the country."
Hoover was right, because security was fashioned according to the status quo, which required the establishment to be in control of everyone and everything. So anything that could upset the status quo was seen as an act of hostility and anarchy.
Your article brings up a common situation in society. One party provokes the other party and then when they respond they are labeled violent. Such provocations go on all the time and, in fact, have started wars. For instance, Hitler attacked Poland to start WWII, and the Japanese attacked Pearl Harbor to begin our war with them in the Far East. Consider, too, what happened with all of the demonstrations following the murders of several Black men, including George Floyd. Donald Trump, a well-known racist, (Time Magazine; https://time.com/5847967/george-floyd-protests-trump/) called demonstrators “thugs,” threatened them with “vicious dogs” and borrowed a phrase popularized by the Miami police chief Walter Headley in 1967: “When the looting starts, the shooting starts.”
Even the Black Lives Matter movement and protests were claimed to be violent, completely ignoring what provoked the demonstrations in the first place.
In my opinion, for what it's worth, the White Lives Matter backlash is a form of violence because it invalidates the suffering of those harmed.
Much of what you cited has to do with this age-old insidious act of provocation to violence; it’s as old as the hills and has been used against Black people in this nation since Day 1. It’s a game that school children use and this describes the mentality and maturity of white supremacists.
Side note: FBI statistics show anti-Black or African American attacks were the most common form of racist hate crime in the United States in 2021, with 3,277 cases. The next most common form of race-based hate crime were anti-White hate crimes, with 1,107 incidents.