First, if you are going to use a tripod, the authorities would like to see your papers. Unless, you have a problem with that. But why would you? It’s not like the ‘authorities’ ever make rules that are overbroad or unfairly limit people’s rights.
Update: Reader Keith Ganey emailed to tell me about a more egregious example from his home town, Seattle. The Police and Homeland Security (thank god they’re willing to surveil the parks for suspicious photography) descended upon a man taking pictures in a park – after he had already obtained permission from the proper authorities.
P.S. If you want a better practice, check out this Ultimate Guide.