Postal mail is historically treated as a special case because it's a government agency. Cars on the street are still your property, even when you're not in it, just as your house is still your property even when you're on vacation.
Wiretaps and documents hosted on the "cloud" are somewhere in-between. The first time the Supreme Court considered the Constitutionality of warrantless wire taps, it found that they were not protected by the 4th amendment. In the 1960's they overturned that precedent, but using reasoning that really only makes sense in an analog context where your voice directly modulates signals on a wire, and there is no intermediate storage.
Call records are further removed still. They're not a recording of your voice. They are generated by the telco, for the telco's own purposes. They are never in your possession, and you don't even know their contents. It's a huge stretch to say that they are nonetheless "your" papers.
Finally, microphones and cameras in public are clearly Constitutional. Whether they can be abused is irrelevant. The 4th amendment is not a prohibition on anything that can be abused. It's a prohibition designed to protect peoples' physical persons and their property rights from government searches.
Generally, safety deposit boxes are considered your property. However, renters in general have a property right in the space they rent, derived from landlord-tenant law. But that property right involves reciprocal rights, liabilities, and obligations. If a bank negligently causes loss of the contents of your safe deposit box, they can be held liable for that loss. When analogizing from safe deposit boxes to the cloud, as many have tried to do (including in legal cases), that whole element of reciprocal obligations is missing.
Do you have a property right in your Google Drive? Do you pay rent? Can you sue Google if they negligently lose the contents? Does Google have any obligations to give you say 30 days notice before they shut down your account? These reciprocal obligations are the difference between renting a garage to store your papers (which would fall within the 4th amendment), and simply leaving your papers in a friends' garage (which wouldn't).
While it's unclear what the line is, it's clear that it has been crossed. When you start needing lawyers to split hairs, it's time to re-examine what you've hatched and ask if it even passes a giggle test.
"Secret court" and "All this stuff we've collected? We haven't actually collected it until we look at it" and oversight by people who are clearly invested in keeping things cozy. This is all madness. How did we get here?
I might not know enough to know where to draw the line, but I know enough to know that it's gone wrong, and that erring on the side of severely restricting this kind of behavior and shedding light on what has happened is probably the best course of action.
Wiretaps and documents hosted on the "cloud" are somewhere in-between. The first time the Supreme Court considered the Constitutionality of warrantless wire taps, it found that they were not protected by the 4th amendment. In the 1960's they overturned that precedent, but using reasoning that really only makes sense in an analog context where your voice directly modulates signals on a wire, and there is no intermediate storage.
Call records are further removed still. They're not a recording of your voice. They are generated by the telco, for the telco's own purposes. They are never in your possession, and you don't even know their contents. It's a huge stretch to say that they are nonetheless "your" papers.
Finally, microphones and cameras in public are clearly Constitutional. Whether they can be abused is irrelevant. The 4th amendment is not a prohibition on anything that can be abused. It's a prohibition designed to protect peoples' physical persons and their property rights from government searches.