It's probably a good idea to add to the existing network of transoceanic cables
http://www.submarinecablemap.com/
but the technical means of monitoring international signal traffic include a lot of other methods besides just having a listening post at the cable landing point, so probably more helpful for worldwide communication privacy is building privacy by design
http://www.privacybydesign.ca/
into every device and every network (and every legal system) all around the world.