Yeah it's just not that easy with the advent of coherent optical communications in subsea networks. You need to be able to do some very complex DSP in real-time at 50Gb/s. You also need to know the exact FEC encoding scheme, grey map, actual modulation format etc... It is very non-trivial. For OOK signals I think it's somewhat doable for coherent, very, very hard. Not totally impossible but I highly doubt even CIA has this expertise.