I hadn't though about before, namely that novel delivery methods must necessarily engender novel methods of hijacking and theft.

My first thought when I saw Amazon's video was a teenager shooting down the drones with an airsoft rifle and pawning off them off. I might be undervaluing how tough they are, but even if it takes real gun, for <$10 of ammo you could net yourself a $5k+ robot after a bit of repairs and robo-brain surgery. A heavy duty net could definitely hold one of these things down to the ground if you're more trap-minded. They're totally ripe for the picking.

With regards to a few other miscellaneous things, I doubt they'd use the same frequency that iPhones, wunderplastic consumer routers, and every damn internet-thing-under-the-sun uses. 2.4 GHz is crowded enough already and switch to 5 GHz isn't going to to help for long in crowded cities as people switch to 802.11n / 802.11ac.

So my lappy might not be able to sniff their traffic any more, but that's not going to stop a determined adversary from buying / building a transmitter on whatever new frequency they pick. It's not legal to use an unlicensed device on alternate spectrums, but neither is hacking devices you don't own.

But while switching wavelengths may change the transmission protocol, it's not going to significantly affect the encryption technology being used. WEP and WPA were doomed by RC4#Security), but WPA2 uses AES, which is pretty rock-solid, and any newer protocols aren't going to use ciphers that have been broken. If you break the encryption being used on the drones, you've got tech that's worth a lot more than amazon packages, or even a fleet of drones. You're better off selling that tech to the highest bidding government agency or sitting a receiver outside your nearest megabank.

It's definitely easier to break the physical security of these things than taking on the behemoth that is cryptography. But hey, who knows how they'll respond if you gag them with frequency jammer!