Well, no, that phrase does not actually inherently have that meaning, but rather it's one possible use of that phrase, another valid interpretation would be the

Well, no, that phrase does not actually inherently have that meaning, but rather it's one possible use of that phrase, another valid interpretation would be the plain english one. Given that AFAICS noone was proclaiming an expectation of privacy in that specific sense, your use in that sense was rather unmotivated, which is why I went with the alternative interpretation. Now, if I had known that you were using the phrase in that specific sense, I'd simply have asked: Where did you get the idea that anyone has an expectation of privacy (in the legal sense), and what does that have to do with the topic at hand (which is people's expectation of privacy (in the non-legal sense))? I think you are completely confusing "what the law (possibly) is" with "what the law should be". This discussion is about what the law should be, but all you seem to be writing is "but the law is this!". This whole discussion exists because the law as it stands is defective, and people are aware of it (or maybe the law is actually fine, but then it at least tends to be mis-interpreted), so your pointing out what the law is is kinda besides the point. My actual expectation is that the postal service does not archive letter meta data and I have good reasons for that expectation. If the current law doesn't mirror that expectation, then the law needs to be changed. Now, if you think the law is fine as it is and as it is applied, you maybe should bring forward some argument for why the law is good as it is and why a change would be bad rather than just state what the current law is. Also, one more point: I would guess that society in general would actually not expect their letter meta data to be archived, and just as it is convention to not open a sealed envelope (a very strong convention indeed, given that it is law, but still it's just a convention in the sense that there is nothing inherent in an envelope that makes the content private - it doesn't really hinder access to the content at all, it's just that for good reasons society at some point has decided "a sealed envelope is not to be looked inside even though it's trivial to do so" when it just as well might have decided instead for a convention of "every sealed envelope is to be opened by the postal service and the content copied and archived"), it should for similar reasons be convention to not archive letter meta data even though that also is trivial to do, and if that is the convention, then all you have to do to "demonstrate that you expect privacy" is to post a letter that is not explicitly labeled "please archive!", just as you "demonstrate that you don't want to be shot" by going outside without a sign saying "please shoot me".