Do you mean something like this? On the one hand, the government blatantly tips its hand about being able to track people and the protestors shouldn't be surprised. On the other, I bet it was still a bit of a shock nonetheless to be one of the people receiving the text, realizing that the govt knows your steps.
Perhaps it would be better to just use walkie talkies and leave the phone somewhere "safe" if one is planning on going to a protest. This way, a mass movement can still be kind of coordinated without revealing participants individual IDs and locations? I realize it's not a perfect solution, but it solves the anonymity conundrum.
Not sure what would be a "safe" place for one's phone, except at home, but that's not gonna help when the cops suspect you're at the protest and bust down your door while you're getting your strike on.