Google has been forced to protect its undersea data cables with a Kevlar-like coating in order to defend them against shark attacks. Dan Belcher, a Google product manager, explained at a Google Cloud Roadshow event that the company's trans-Pacific fiber-optic cables were wrapped in the material partly in order to keep them safe from the creatures' teeth.
Sharks have been drawn to undersea fiber-optic cabling since the connections were first laid down. The New York Times reported in 1987 that shark attacks had caused the failure of four segments of brand new cabling, and an experimental cable placed in 1985 was discovered to have shark teeth embedded in it. The behaviour has been observed more recently, with footage from a remotely operated submersible uploaded in 2010 showing a large shark clamping its jaws around a segment of thick cabling, before swimming away.
There's no conclusive reasoning as to why sharks are trying to disrupt our internet connections, but it's been theorized that they are drawn by the magnetic fields generated by the high voltage running through the cables. Sharks have a biological ability to detect electromagnetic fields. The ability, called electroreception, usually allows sharks to detect the weak bioelectric fields generated by fish so they can hunt them down in the ocean. But while most cables are shielded to supposedly prevent such electrical fields from being detectable, it appears the sharks may have some way of picking up the signals, leading to the predators getting mixed up between miles of undersea cabling and a meal.