If you're a parent there is not doubt that you worry for your children's future. I would guess that you may worry more for your daughter than for your son? Perhaps, it depends on the situation you may be contemplating.
Daughters have a higher probability of being victims of violence (of many shades) and as a father of a little girl I worry for her safety always. There is a particular evil which really scares me... serial killers. And if there was ever a picture which encapsulates what a serial killer looks like it would be the picture of Joe Metheny. Just look at this guy - there is obviously something wrong with him.
At a weight close to 500lbs and with a large frame - even as a man I would be scared to tangle with him. Imagine our little girls coming across this monster. I shudder at what the victims of this beast went through.
I don't want to go through the details of what he did to his victims (truly disgusting), this may glorify his actions. Instead, I wanted to provide one image which shows the face of pure evil.