Cable tapping is easy
"Tapping fibre at the bottom of the sea? With robots or in scuba gear, through an armoured cable, and all without being noticed? And they didn't fuck up once and get caught? "
The US has been tapping underseas cables for many years. Nothing new.
E.g.:
http://www.theatlantic.com/international/archive/2013/07/the-creepy-long-standing-practice-of-undersea-cable-tapping/277855/
http://motherboard.vice.com/blog/undersea-cable-surveillance-is-easy-its-just-a-matter-of-money
And before that, going back to the early days of cables for teletext, etc., cable tapping has been going on for many, many years.