[DasIch]

I've been wondering why know one hasn't written an application yet that breaks into a W-Lan Network as an alternative to typing in a password.

Obviously there are some legal considerations in certain countries regarding development, possession and usage of such an application but the risk seems to be rather small if you restrict network services, change the MAC and use End-to-End encryption. Besides you might even get away with calling it a tool for penetration tests.