I have tried to make some sense of the various threads on this question and this is my own conclusion on what is ok to carry in the above two locations. Folder; under 4" blade, single edge, cant be flicked open, concealed out of sight, does not look like a dagger. Fixed blade; under 4" blade, single edge, concealed out of sight, does not look like a dagger. Which would be better alternative, the folder or fixed blade. I am old fashioned and actually use a knife during the day for various tasks....defence is not the main reason for carry. I intend to visit many of the usual tourist spots in NYC, at which of these spots do you have to go through a metal detector at the entrance and would you have your knife returned on exit or actually confiscated.