I read they were in Armonk, Greenwich, Jersey and Queens. A perimeter around Manhattan.

The article:

Armonk and Greenwich don't really make sense if the idea was to create a perimeter around Manhattan.

	▲	kylecazar 4 hours ago \| parent [-]
		The idea being there were caches to the West (Jersey), North (Armonk and Greenwich) and East (Queens). The article mentions a "circle around NYC's cellular network infrastructure".