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

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.