I'm a customer of the very best US ISP (sonic.net) in San Francisco. We had a major power outage affecting a quarter of the city, including my home. Everything went down. Except my sonic.net fiber ISP. I asked the CEO how that worked and he responded
> Our network is a “passive optical network” in the outside plant - the cabinets on poles just house optical splitters - no electronics.
Yes, apparently it's glass all the way from San Francisco to San Jose. I'm assuming they aren't using this power over fiber trick either but it's neat to think they could, at least for limited power needs.