Probably none. Antifa and BLM "ONLY" did close to two billion in damages, killed scores of citizens and murdered a cop. AND they rioted and looted for MONTHS.
What's that compared to a demonstration where LESS than one half of one percent were violent - and the violence was OVER in less than two hours... WITH LESS THAN $10,000 WORTH OF DAMAGE?
Come on - which would YOU expect the FBI to be concerned about? Months of violence or hours of violence? Billions in damage or %10.000 in damage?
Oh, and I forgot to mention Antifa and BLM were 'gifted' pallets of bricks, weapons, and walking around money... so there were an organized force of chaos... NOT a peaceful group.
Face it, the FBI is a thug arm of the democrat party. In a few years we'll call them 'the secret police' or the SS or KGB... they're goons in transition.
Here is a list of people that were arrested. I’d be willing to bet that the worst of these are not trump supporters, for the most part.