Just make sure you record it.
Of course, like so many other things, it's kind of security theater. If you had a small band of thugs, well armed, you could sneak up on the building from a half dozen angles and take those guys out in 60 seconds or less.
There is no fence around the cemetery itself. There is only security in the visitor's center. So I'm not exactly sure what they've "shut down" unless it's the visitor's center.