We don't know that, no one has counted. There were tens of thousands of people there, how many were Nazis? We don't know how many of them are there in the US, for that matter.
What we do know is that they have no real cultural influence or power. That's why calling them out as particularly dangerous is an act of politics. It attempts to smear political opponents by grouping them with evil figures like Nazis, white supremacists and racists.
There were people with using nazi symbols in the protest. People wearing nazi symbols are historically violent to certain groups of people. That's enough reason to alert people in the vicinity about it.
At my work's Slack I get snow alerts, heat wave alerts, lockdown alerts. All those can be politicised depending on the audience, but are still highly appropriate to be had on a company's Slack channel.
You don’t think that in the midst of a terrorist attack in which multiple perpetrators bear Nazi symbols, people in the area should be at least slightly more worried about Nazis than usual?
