Hacker News Reader

https://en.wikipedia.org/wiki/Dark_fibre

> A dark fibre network or simply dark network is a privately operated optical fiber network that is run directly by its operator over dark fibre leased or purchased from another supplier. This is in contrast to purchasing bandwidth or leased line capacity on an existing network. Dark fibre networks may be used for private networking, or as Internet access or infrastructure.

They GP talked about "installing a decent amount of dark fiber" not running a network over someone else's unused fiber, which I think is the "network" part of your quote.

Bloomberg and co buy lit, dark, and switched products. In NYC, they purchase these products from the incumbent players.

I take it to mean they roll out their own physical fiber, and don't just lease or ride someone else's network.

The term 'dark fiber' is also used as a product to be bought from a network company, which the customer (in this case bloomberg) then lights up themselves.

It's sounds more secret and cool?

You're right.