That is a good idea as long as the radio signal is well encrypted and the device itself is tamper proof.
I suspect that malicious hackers have used this sort of thing for many years. If you set up a directional antenna on a hill overlooking a large metro area, you can scan around and find a number of unsecured wifi routers. Send a few million spam emails on one router then move your antenna over an inch, send a few million more, repeat. After an hour, shut down your signal and move to a different hill. This new innovation seems to add a layer of obfuscation to the process that make it much harder to trace the signal. I also suspect there will be many more evil users of this technology than legitimate users.
i want it. can i use it to log on to my local library wifi, thats just out of range? i guess this beats the cantenna?