The speaker paused, startled, as something flew through the air a few meters away. A beer bottle smashed against the side of the building, painting the smoked glass wall with a trail of foamy liquid. She pointed her megaphone at the portion of the crowd from which the bottle had come. "Please!" she urged them. "This is meant to be a peaceful protest. Let’s keep it that way! We don’t want to give the police any excuse to—"