To respond to your edit: no, you just shouldn't bring your phone
You can't harden your phone against every hypothetical because you can't think of every hypothetical and it's dumb to think you can. Why would you think you alone can outsmart teams of very well-paid people who literally sit around all day thinking about ways to track you using your phone?
Your phone literally can't even have signal without your carrier knowing where you are, so why bother bringing it?
Are you seriously here to tell me there are no uses for a cell phone without signal or Internet access, when the most common use for cell phones at protests is taking video?
To respond to your edit: no, you just shouldn't bring your phone
You can't harden your phone against every hypothetical because you can't think of every hypothetical and it's dumb to think you can. Why would you think you alone can outsmart teams of very well-paid people who literally sit around all day thinking about ways to track you using your phone?
Your phone literally can't even have signal without your carrier knowing where you are, so why bother bringing it?
Are you seriously here to tell me there are no uses for a cell phone without signal or Internet access, when the most common use for cell phones at protests is taking video?
Then bring a camera that can take videos?