This is addressed to the copious negative top-level comments.
As someone with first-hand experience attending a computer summer camp, I think this is important.
I attended a computer summer camp as a kid. It was all male and had an very awful culture (e.g. lunch conversations were pretty pubescent and gaming was really important). The culture seriously turned me off, to the point that I stopped programming entirely and got into math for a while afterwards. Oh, and I'm male...
If a girl joined any random summer camp 12 years ago, she would be the only girl in the group. This may have changed since then, but I'm sure not by much.
Sense of belonging and community is important, and it's not unreasonable to suspect that a male-dominated summer camp would not provide a girl with that sense of community. Especially at that age.
A more ideal solution might be increasing the number of girls interested in computer science so that this simply is not a problem. Unfortunately, it's unrealistic to assume that will happen over night. In the mean time, camps such as this might decrease the social barriers to entry for girls interested in CS. That's a Good Thing.