JFK last year, after a misconnect due to weather. There were hundreds of people trying to sleep all over the airport, and the security guards would constantly come by and tell us we aren't allowed to sleep, so we migrated to someplace new and slept there. I was almost arrested by NYPD (on what grounds im not sure), but I just kept getting on the train and going from terminal to terminal until i found somehwere to sleep with relatively few interruptions.