We need to talk about data as a physical object.

We need to admit that it isn't and that that's a terrible metaphor.

It’s still saved on disks somewhere, whether they’re a traditional HDD or a modern SSD.

Yes, often multiple copies are saved. Sometimes it is aggregated with other data, sometimes not. Making a new copy is insanely cheap, and, under the hood, even when just moving the data from the hard drive to the computer's memory, a copy is made automatically. There's no way to avoid copying the data.

But, to make it clear, "data" is basically "ideas", and you can't really treat ideas as objects. For thousands of years the idea that you could control ideas was ridiculous. You could control the physical object that an idea was expressed on, but if someone took their own time and copied it, that was a new object and the person who made the original had no claim on it.

Copyright, and its evil friends, is a relatively new concept where the government grants a temporary monopoly on the expression of an idea. Stealing the physical object on which the idea is printed is one thing. But, now you can get in trouble for "stealing" the idea. That's what you're talking about with stealing "data", is that what you're supposedly "stealing" is information.

But, of course it's not theft. When you copy an idea without permission, the person with the original doesn't lose it, they just lose control over a copy of that information.

Treating ideas, data, etc. as physical objects just never works because ideas can be copied without the original person losing anything. This is different from physical objects where my taking it necessarily means that you no longer have it.

In other words, data was always as physical as words on the page of a book.

Not at all, because each copy of a book is its own physical object. Copying a book is difficult and requires its own printing press. Even a low-fidelity copy like a photocopy requires a photocopy machine, ink and paper. Copying data is essentially free. When copying a book required a printing press, you could sort-of pretend that ideas were objects because copying was so burdensome. But, with digital data it's clearly ridiculous. That doesn't mean you can't have laws about data (i.e. information), it just means that those laws care going to have to be completely different from laws about physical objects.

Why did we accept the change in how ownership worked simply because of a change of storage medium?

Because copying is essentially free. It's no longer an object, it's information.

But, having said that, the storage medium isn't a major issue. The real question is when did people start accepting that you could treat ideas as objects. Stealing a book out of someone's backpack and photocopying a book are completely different crimes. In one case, the person no longer has the object. In the second case, they still have it, but they don't have control over the copies of it.

Talking about data as if it's an object or something you can own is a red herring. The real issue is privacy.

For instance, say you use a period tracker app, that is owned by an non-profit, trying to use the data to better understand women's hormone changes so that they can get better medical care. Great! Ok, now what happens if that non-profit goes bankrupt and as part of the bankruptcy proceedings sells its data to Meta or Google so that it can afford to make payroll. Well shit, your data is now owned by them, and you're out of luck.

A privacy rule handles that situation better. You can give the company access to your private data, and then revoke that access later. If your data is something they own, they can use it however they like. But, if you own your own privacy, it doesn't matter if the period tracker app gets bought out or goes bankrupt or whatever. The data they have isn't something they own and can sell, it's private data that they had temporary access to.