Maybe a group on behalf of a nation state is testing out its muscle. Or sending a warning. Maybe the UK did something recently a nation didn't like, and this is the new form of "diplomatic protest". Or sending a warning shot.
I remember reading last year that the large Delta airlines outage was cyber terror related.
It really feels like we're not too far off from a war between two nations without a single bullet fired. What happens when a country is hit with nation level ransomware? Ie not, "give us $300 bucks and you'll get your PC back", but "sign XYZ treaty and you get your country's water system back"? Or "we'll restore your internet and turn your powerplants back online"? How much will a wealthy country (like us in the US) be willing to stomach of seeing people going thirsty and hungry before they want their govt to capitulate?
Of course the world will condemn and complain, but as has always been the case the country with the largest Army makes the rules. And we might be using the wrong measuring stick. Microsoft missed the boat by thinking (along with most of the industry) that measuring computing meant measuring PCs. It wasn't until it was too late that it realized that computing was about to be dominated by Mobile and smaller. They were using the wrong measuring stick.
Are we on the verge of an era where an army should be measured in its digital strength and not its physical strength? It's a very scary thought.
As an American I think first of the risks to my own country. How long could we sit with a nationwide blackout, and the internet down (for anyone using backup generators)? Food rotting in shipping containers because no cranes can offload it. No easy communication or flights for quick way to move people or things around.
As a country (and as a world) I can't help but feel we're really not doing enough to take a risk like this seriously. It's just a feeling, but based on small incidents here and there it really feels to me like something in the next 5-10 years is gonna happen that'll make us all drop our jaws and say "I didn't think this was possible."
Regardless of your political beliefs, a lot of people around the world didn't think last year's US election was possible. I was shocked by it as well, but it also opened my eyes to how much more really is in the realm of possible.
As engineers we have much a deeper knowledge of the risks involved and as a result a much greater responsibility of raising awareness and getting the problem fixed.
EDIT: I'm not sure of the original location I saw the Delta stuff, but a quick look now turns up this link.
http://observer.com/2016/09/did-a-cyber-attack-ground-delta-...
And yes, I'll repeat this above comment is purely speculative by me.