They probably get half of the strands, to mirror all the data passing through the other half.

You don't need a full 1:1 mirror of the strands, you can probably filter off a lot of the traffic that you don't need to spy on (e.g. TCP overhead) compress it and use a fraction of the bandwidth.

or Youtube streams...

That were my thoughts before, or at least how I'd do it:

- seal deals to get x strands

- tap it while still unlit

- mirror what you need and exfiltrate directly over your own private strands

- profit

Somewhere in-between those points, I'm guessing:

https://firstlook.org/theintercept/2015/07/01/nsas-google-wo...