I'm not sure sympathy is the right reaction. Israel is doing what it must do. Every single "Palestinian" casualty is the direct or indirect result of Hamas' actions. Every one. The international campaign to get Israel to stop its military actions is preposterous. If Hamas were to publicly state that it is ceasing hostile activities against the Jewish State (and lay down their arms), the fighting would stop in an instant. Why is the international community not begging Hamas to stop fighting? If Hamas would stop the rocket attacks, Gazans could live in peace. Simple as that.
There are theoretically some Palestinians who just want to live their lives peacefully and without undue interference or hindrance, and they deserve some sympathy, but it appears that these are very rare individuals indeed. Virtually the entire "Palestinian" community - West Bank and Gaza - has been raised to hate the Jewish State and everyone in it. The only solution is a drastic one: a police state, where everything in that community is regulated and controlled, by force if necessary.