We love that so many parents send their little girls to our courses; statistically it is indeed true that young females are most vulnerable to kidnappings, sexual assault and domestic violence. However our sons need empowerment also!
This is not only due to the fact that:
a) Opportunistic predators will target any gender of victim if they get the chance
b) Boys have proclivity towards fighting with one another and aggression is a part of the socialization process for males. This means your son is likely to face a physical altercation at some point in his childhood
c) While the rates of abuse towards girls may be higher, abuse towards boys also occurs and is far too high for any degree of comfort. As we always say, even one child is too many and this of course applies no matter the gender
In addition to the above, one very big reason why you should teach your sons self defense is their disposition towards RISK!
I touched on it in a previous post; most boys enjoy taking risks, and are also impressed by other boys who take risks. Much to our chagrin as parents, boys will often seek out risky situations just for the sake of it! 
To compound this, boys are also more likely to disobey their parents when told not to do something risky. They are notably more attracted to violence and conflict, and are readier to fight and to respond aggressively than girls 
All this means your boys are likely to find themselves in many difficult situations throughout childhood, for which self defense and safety skills can literally be the difference between life and death. At the very least it can be the difference between a lesson learned and a lot of hurt 
So empower your boys! Because one child is too many 
