Andrew's a NUT, and we all know it
Note that lately, they check your boarding pass at the entrance to each pier and if your boarding gate is not in that pier, you will not be allowed past the security check.
This means you are effectively confined to the pier where your flight departs from or you could shoot from the main terminal building connecting the various piers.
Previously the end of pier 5 was excellent as it had floor to ceiling glass panels. Lately, this area has been blocked off as a holding room for flights at the end of the pier. When no flight is boarding there, you may be able to go to the glass for photography. Give it a try, for this is where you get nice rotation shots on 21R.