I don't understand why Moments like these happen. I learn from it. It's not fair! I am just not going to sit on my ass like a pansy blaming God!
For me, the problem is that he could stop bad things and he doesn't do it. If my kid were about to be run over by a car, and my friend just stood there and watched it all -- fully capable of running out and grabbing my kid and saving him -- I would be angry with my friend. Since God supposedly knows everything, has complete ability to do whatever he wants, and can do it at no risk or cost, it seems unjustifiable for him to let these things happen without stepping in.
The other side of the argument is that he has his reasons for not stepping in and we just don't understand them yet. There's really no way to argue against that, since it presupposes there's information that's unavailable. Some people start with faith in god, and accept that he has his reasons. Others start with nothing and demand a reason to have faith. It's the latter group that can't accept a God concept based on his allowance of such things.