Oh, the irony.
Video thanks to Maggie's Farm, on which I ain't gonna work no more, where there is this explanation:
Israel is a democracy, with rights of free speech, petition, and protest. The tiny number of far left Israelis are vocal and often ally with radical Arab-Israelis. In this video today, they held a protest in Jerusalem against Israel bombing Gaza. Then, they scurried away as soon as the air raid siren went off that a rocket may come in from Gaza.