Most likely causes I would think are:
A critical hardware failure inside Sky's network infrastructure.
A data centre outage.
The third party responsible for deploying streams with DRM has experienced an outage.
Someone has accidentally dug up and cut through some multicore fibre optics.
A coordinated effort DDOS attack on the front end services used inside Sky's Network.
A coordinated effort DDOS attack on the back end services used for content delivery and DRM.
Whatever it is, Sky either does not have a service failover plan or they do and they've just discovered it doesn't work.
I would not want to be network engineer at Sky this evening.
I seem to recall that Sky outsources the content delivery to a third party.
My puck is continuously power cycling so whatever service normally advertising stream availability isn't working. Which just goes to show how dumb those boxes are. It's a bit like a terminal client used RDP or Citrix, if it can't pick up a service advertisement it's a dead stick.
