What authority is needed to take pictures?

"C J Campbell" wrote in message
...

"Peter R." wrote in message
...
Nomen Nescio wrote:

"You have to leave, NOW, sir!", he replied sternly.

Now this brings up an interesting question. Are we, as US citizens on
public land during peacetime, required to abide by the orders of
military personnel?

On what grounds did he have authority over your actions and location?

None whatsoever. Nor did he have authority to take pictures.