This should be named: Data transfer through power lines. The rest is just accessory since the machine has to have the exploit already installed.
Impressive engineering, impressive bitrate, but not so novel an idea, overall.
But this exploit would create, out of thin air, a physical connection to the outside world using the power outlet the machine is connect to.
So unless data centers become powered by solar panels or generators that are themselves under the same level of physical security as the server racks, then this is a pretty serious exploit.
See https://www.usenix.org/conference/usenixsecurity15/technical... by some of the same authors.
Then also put some shovels, pickaxes and other construction and digging gear into the back of the pickup truck.
Lastly, learn how to not behave like you're doing something forbidden or bad. You can try it out in less secured areas if you want to train up a bit.
Once you've mastered that you can drive up to any place and start digging. Nobody will question it.
The same is also true for IT security. Pentesters do that sometimes; walk into the bank, walk up to the manager office or similar, wait for a few minutes, then walk back. Everyone will now assume that you talked to the manager (provided they didn't see you standing there) and you can do things like "can I plug this USB stick in? I'm from IT and were updating the anti malware software in all branches." (that actually worked, there is a DEFCON talk somewhere)
So in conclusion; don't be confident someone won't dig up your powerline and start tapping it. Unless you have a habit of talking to the construction workers if they're allowed to do dig up the road.