Yes, you could jam the wireless signal, but that would only shut down part of the network. You would need multiple devices everywhere that the network exists to comletely shut it down. This becomes very difficult when we think of the network as being city, state, country, or wold wide. Also, the jamming could be bypassed by changing the the frequency of the wireless signal. The jammers would need to be adjusted to compensate for the altered frequency, and then the networks signal would just be changed again.
In my opinion, the internet's future will consist of privately owned satilites that act as relay nodes to distribute data throughout the network. Right now you can send your own satelite into space. Given that space is now privitized, it's just a matter of time before nerds like myself start setting up their own internet.