two security-related things that stuck with me were:
a) there is a door that leads to the reactor compartment, and that entire section of the ship is off-limits to him. he had a thorough background check before going, and someone from the Navy reviewed all his footage before he could publish it. but despite all that, he's not allowed to even be in the part of the ship where the reactor is. excellent defense-in-depth (pun not intended).
b) when discussing sonar, the XO was sitting right there along with the sonarman, to make sure nothing classified was recorded. there were a few times where the XO said "nope nope nope, can't talk about that". the most interesting one to me was, IIRC, a question about the active sonar system being relatively high frequency sound, and if they used any lower frequencies...they cut immediately after that.