And as a practical matter, the legal status of online information needs to catch up not just in the police context. If Public Storage loses the contents of my locker due to their negligence, I can sue. Can I sue Google if they accidentally lose the contents of my gdrive? Can I insure the contents of my gdrive?
Lawmakers use analogies because they're conceptually very powerful. Say you have two things: 1 and 2. 1 has characteristics X, Y, and Z, and 2 has characteristics X, U, and V. A rule applies to 1 because of characteristic X. Analogizing from 1 to 2 on the basis of the shared characteristic X is an intuitive (and logically valid!) way to argue that the rule should also apply to 2. Not because 1 and 2 are identical or even very similar, but because the animating force behind the rule is the shared characteristic X that is present in both 1 and 2.
Physical-to-digital analogies are very dangerous in a lawmaking setting because lawmakers rarely understand the implications of applying a physical power they wield in the digital realm. Examples include the lobbyist-proposed law allowing IP owners to infiltrate others' computers and delete ostensibly stolen files, while simultaneously destroying the entire concept of digital security, and the DMCA making it illegal to recycle printer cartridges or switch cellular carriers.
[0] Yes, I know that is the technical term for data about data, but there are plenty of examples where technical terms and legal terms differ in definition, intent, and hidden implications.
Except they're not personal at all, being visible to god knows how many intermediaries and being recorded in plain text for any sysadmin to see. Maybe we'd like to treat them as such, and legislate accordingly, but that's not their inherent nature.
I think the problem here isn't lawmakers not understanding the implications of digital technology, but technologists adhering to a romantic view of technology rather than a literal one. Forget the law, forget the philosophy, just look at the mechanics of the process. Reading a web page is not a private act. It involves plain text communications over public networks through intermediaries to a host that is free to and does record identifying information. Privacy is not a core tenant of the internet protocols, whether you're talking about TCP/IP, HTTP, or SMTP.
This is not an example of an impedance mismatch between a technical term and the same legal term. We don't treat mailing addresses the same and e-mail addresses the same because they both have "mail" in the name. We do it because both have the characteristic of being routing information visible to third parties outside the communication. The idea is that routing information can't be all that "deeply personal" if you voluntarily expose it to a bunch of people. It's irrelevant whether its digital versus physical, or whether you call it "metadata" or something else, or whether the "bunch of people" is the postal service or your e-mail hosting service.
If a jewelry store puts up cameras to track people in the store, the jewelry store owns the footage and information. If Google tracks user queries, Google owns the tracking data (even if its about me). If I buy a storage locker, a warrant is needed to open it up without my consent. If Google "sells" me data storage either directly or indirectly, I assume I own the data stored within and it should take a warrant to access it, regardless of how easy it might be for the superintendent of the service to access it.