I am both a private pilot, as well as an FAA approved commercial drone pilot, as well as former military member where I assisted in counterespionage. I only provide this as background experience, not as authority.
I have totally dismissed all this paranoid mess for quite a while. However, as I've listened to the public statements from DHS, FAA, FBI, military, etc. as well as listening to the (non-crazy, non-idiot) reports that have been documented, I've slowly become more concerned.
The only thing that seems (to me) to fit everything would be the U.S. Gov having received reliable intel that something highly undesirable came in through a NJ port. The Government is quietly trying and located it without alarming the public.
It is entirely likely that 99% of politicians and Gov't folks do not have a clue what is going on. That is how a TS-SCI program works (top secret - secret compartmentalized information). TS-SCI comes into play whenever there is highly sensitive information that could pose a significant threat to national security if released, sometimes this is special intelligence, sometimes this is tasking orders, and sometimes it is active field operations.
A number of sightings can be dismissed fairly easily in my view. Others cannot. The interesting public reports have been the low flying "SUV sized drones" with loud motors, as this indicates something similar to a Boeing CAV which weighs in at 600lbs or 1100lbs with a large payload. Amateurs do not fly these. These are intended for serious work and cost millions of dollars each. The reports of these flying patterns at low altitude likely indicate they are being used as sensor platforms. Photo or video make no sense at night. Low altitude doesn't make sense for RF scanning. Scanning for radioactive material however seems entirely plausible.
Last year there was a similar use of drones and vehicles carrying specialized equipment to locate and recover radioactive colbalt-60 that was discovered missing in Western Australia.
Given that the sightings started around NJ and recently expanded to the surrounding States, this sounds a lot like a coordinated search that started at the ports and has now expanded. The search is being done at night, when air traffic is lightest, public is sleeping, and drone lighting make capturing clear photos difficult (not necessarily intentional).
It really appears to me that there could (and I stress COULD) be intel of an NBC threat (nuclear, biological, chemical). I do not factually know this, nor I do not have any inside sources. That said, when a reasonably intelligent person considers the totality of the available information and apply Occam's razor, it seems reasonable. The State of global affairs and politics only increase these concerns.
Apologies for anyone thinking I'm spreading conspiracy theories, but I am sincerely open to any other rational ideas that consider all the available data and provide a more logical result.