My opinion is that standing up for the current abhorrance of police violence connected to BLM is worth some endangering behavior on their own choice (i.e. going out in crowds, because it's a multi-100 year problem), whereas getting a haircut is not the same, but I see why that's contentious. 1000 more people getting a positive case that wouldn't have otherwise will lead to a few deaths, and they will spread it and kill a few more. It's personally horrible to just write down that fact and not know what to do with it.
1. https://bing.com/covid/local/washington_unitedstates
2. https://www.doh.wa.gov/Emergencies/NovelCoronavirusOutbreak2...