>For the overwhelming majority of people I don’t think there is much yet to worry about in simply attending a protest (Assuming you’re a citizen and you act sensibly because otherwise that’s an entirely different threat model and you probably shouldn’t be there at the moment).

That seems a tad naive. I think being recorded by local/Federal agencies at a protest, especially one critical of current government actions, is a legitimate concern. Especially since those tools are being brought out specifically for the protest, not because they are looking for some murderer that happens to be a block away from you.

Also, the word "yet" is doing a lot of work there. Considering that data can be stored indefinitely with little oversight, there is little to stop police from searching through the database and looking for "targets of interest" like phones that showed up to multiple protests.

Being at a protest is already known to make you interesting, which is why those tools are being brought out in the first place, why police are "friending" protest organization FB pages to gather membership data, etc. Keeping yourself out of databases that could be used later to jam you up is reasonable. There is also no way for police to tell who has a phone and who doesn't at a protest, so you aren’t highlighting yourself anymore by not bringing your phone (or turning it off), unlike say wearing a mask and sunglasses to reduce facial recognition visually highlights you.