Why wouldn't they just drop their equipment and leave? Cutting cables causes a noticeable outage and requires people to physically visit the point of modification, which ruins the covert potential for such equipment.

Possibly there's no way to install the equipment in a way that won't interrupt service.

Also, such an approach would give the fiber company plausible deniability if they were ever called out for supporting NSA data collection.

unless you your install is downstream of the cut and action of the cable cutting is both to interrupt service and to cause a distraction...

Or, going down the rabbit hole, the government sabotaging fiber lines to stir up public support for "protecting" the internet, more surveillance, etc.

The quote keeps getting kicked around on most media outlets: "Our internet infrastructure stands practically unprotected".

I've never heard anyone use that in terms of physical infrastructure. I've heard our other physical infrastructure is unprotected (which is true) and our internet isn't protected against cyberattacks (which I guess is vaguely true?)

It sounds crazy, but at this point, why not.

"Who can protect your internet better than the federal government of the USA?"

GCHQ :)

I vote for this being fully private operation - someone trying to sabotage their competition, or some HFT shenanigans.