answer:well, fiber optics is quite delicate, but as i understand it the cable has plenty of armor on it. if anything it going to hurt it i imagine it will be volcanic eruptions, earthquakes and other disaster level events. as for sharks and other animals i doubt they could damage it. and its probably so deep, that is any terrorist had the capability to reach it, they would also have the capability to mess with us on a much larger scale than underpants bombs and shoes full of explosives. i imagine to intercept it you will need quite a bit of technology, otherwise all you are going to get is little pretty lights.