Bobbing and Weaving
I noticed they plan to "Pin" it to the ocean floor. I would think it would be wiser to attach to a more mobile platform in the ocean. We already track "Space Junk". We know their orbits, a mobile platform would allow the whole thing to run a pattern weaving it around the space junk. A no fly zone easily handles basic air traffic on earth. This is tech that is a long way off, but not impossible. Of course, powering the system would be plenty tough. The Cable has to be very light weight or it would fall apart under its own weight, thus the need for Nano-Carbon tubes.
