This reminds me of some not-well-formed thoughts that have been bouncing around the back of my head for a while.
They start out something like this: Police should not be a special class in society. They should not have any right not accorded to the general population.
Exploring that leads to thoughts like, "I can't just walk into my neighbor's house without their permission. Neither should police." and "I can't shoot somebody and walk away without consequence because of some emblem on my shirt. Neither should police." "If any action would lead to a particular consequence for regular people, it should lead to the same consequence for police." What's the consequence of systematically recording video of people walking down the street? Should it matter if it's done by a homeowner, a school administrator, or a police officer?
Pondering further, I come up with, "Police should be able to enter my house with a properly-served warrant. Should the general populace be able to do the same?" or "Police should be able to shoot suspects holding hostages in a blundered bank robbery. Where is that line for regular citizens? We really don't want that, do we?" Imagine if, for example, somebody were to embed themselves in a clock tower at a university and start shooting away. Campus security doesn't have any way to intervene. There is no SWAT team in the region. What if your friendly neighborhood deer-hunter takes it upon themselves to decide who the culprit is and use their own scoped rifle to return fire? Do they have the same legal protections as a police officer doing the same?
In the context of this thread: Diplomats can send encrypted communications. All people should have the same right. Journalists, by virtue of being people, should have that right. They have the right because they are people, not because they are journalists. Same for any other privilege.