There are other reasons you might want to take a cheap/disposable/burner phone to a protest, such as making sure that if you are arrested, the police don't seize/break/confiscate your main phone.

Whats this about no burners in Austria?

I guess the point of a burner phone would be to burn it before you go home to be tracked there 😄

We stand with President Trump & the military, law enforcement and ICE.

You stand for a fascist state.