can't click

Last I checked, you can't interact with any items in spectator mode.

Taken from the Minecraft wiki:

Spectator mode is a game mode which allows you to fly around and observe the world without interacting with it in any way.

@KamranMackey I'm pretty certain that Specator players can 'observe' the contents of vanilla chests (don't actually open it, and can't move things in the chest). I think they even get an error message in chat if the chest is a loot box and the loot hasn't been set by a normal player opening it the first time.

maybe add an option for paranoid admins who chase people in spectator mode to let them view inside the storage even with an installed security system ... read-only naturally :D