Apropos of absolutely nothing, a few random pieces of advice that you may or may not wish to follow.
I would also suggest you travel to the protest on foot, or by public transportation. If that’s not possible, park a good distance away and walk in. If you’re ubering (or whatever), have them drop you at a business a few blocks away. Makes it harder to link you to the protest later.
Also get the number of a good lawyer and write it on the back of your hand in marker that won’t rub off. Pieces of paper can be taken from you. Your hand can’t.


Test your faraday bag. And test all the radios. (can you see your phone inside the bag via Bluetooth, WiFi, cellular [on 3,4,5g], NFC?).
I have one bag several years old that is leaky and stopped working. Some kind of hard case is probably more reliable. Real science-grade faraday boxes of all sizes and forms are available, but they are $$$.
Know that there are a ton of alternatives to carrying a smartphone when you need to maintain comms, but they all have their own pros and cons and most come with a monetary cost and a learning curve, depending on the tech.
Whatever you do, if you play with radios AT ALL, and you plan to transmit anything AT ALL (listening/receiving basically anything is almost always fine) - get to know the band plan and where you’re allowed to play. always know your frequency/power level, be mindful of who might be listening in, and stay WELL away from government/military and even commercial comms channels. The airwaves are a really difficult place to regulate properly, but you will suffer the full weight of the FCC and others if you start causing problems there. don’t intentionally interfere with other civilian users either.