I would think they would be able to pull a conviction if they tried, There must be some small silly law he broken if you search the massive law books...
Yeah, thirteen cases of wire fraud. However, the portion I worked on was the network intrusion. I was the one who caught the guy and found out who he was. The point is, yes, they can nail him on wire fraud, but that was ancillary to the orginal scope of the investigation, and that was him accessing the county network without permission. Unless you have posted warnings and discaimers somewhere on your network (the criminal does not have to necessarily see them, they just have to be somewhere) it is not a crime.

Furthermore, information broadcast over the air is even on more shaky legal ground. It is considered to be publicly accessible. And the assumption is that if you are not going to protect your network, it is not illegal. If the information is encrypted, then it is considered to be private, even though it is travelling over a public medium.