There are different non-disruptive techniques, two known methods being "shaving" the cable and the other involves bending the fiber optic cable at certain angle

There are different non-disruptive techniques, two known methods being "shaving" the cable and the other involves bending the fiber optic cable at certain angles. I wouldn't be surprised if there are other esoteric techniques that somehow allow NSA to monitor emanations through an intact fiber optic cable and its shielding.