The book touches on laws that are supposed to protect us, but do little but diminish our ability to protest (The book is set in the US, but similar laws apply in the UK).
Special measures supposed to prevent civil disobedience can easily be twisted to break up legitimate an peaceful protest.
I must confess that I am very likely to ever go within 5 miles of a protest, but a heavy handed "lawful order to disperse" can easily turn people expressing a grievance into an angry mob. Police tactics sometimes seem designed to aggravate the unsteady.