Like London, the Newark airport closure due to civilians drones is a lark. The story says the drone was sighted at 3500 ft. Civilians drone have a battery life of 30 minutes or less which is greatly reduced in cold weather. A drone normally flies below 400ft. A climb to 3500 ft would not only use the most of the battery but it descends much slower than it climbs, and in freezing weather likely could not go straight up 3500 ft and land safely much less fly from off-site to get to the airport. I say this as a FAA licensed holder of a Remote Pilot certificate. The reason the airport is being shut down is not drone related but mostly likely just a cover story.
https://www.zerohedge.com/news/2019-01-22/newark-airport-ordered-halt-flights-after-drone-sightings