Could be, but why scan bags from ALL flights?

Yup, that's what I said...same flight

When we arrived on 1/3, there were long lines to leave the airport (after picking up our luggage) on the left side. We took the right side and just walked out. Not really sure what that was all about. Arrived from Newark

Got in yesterday, it took no more than 15 minutes form the time we exited the aircraft to get our bags and exit the airport... Customs were basically instant and no scanning for anyone...

You're correct. I have NEVER seen this room used! A few months ago though, I started hearing about it being operational after hearing about it through the rumor mill. When I asked some questions very few had heard about it and were confused, so I was second guessing myself as to what I had heard. Sounds like it is random and not all flights but it has been going on for awhile.

When we arrived last March on a Sunday on United out of EWR it was in use. Long line if you can call it that, but eventually they began just waiving people through. I also believe (without any foundation) that it has to do with flights arriving from Central/South America or other islands where drug activity might be suspected.