> The difference that ownership would give is consent. Western liberal democracies are based on the idea that you can do what you want as long as all parties agree to it.

No, there are things that two parties cannot legally agree to do even when there is a stated agreement between those parties.

Most of these things aren't legal because society has recognized the immense harm or potential for harm that they have.

For example, you can't legally sign yourself into slavery, nor could you (as a minor) sign a contract with an adult which would make sex legal; even if all parties say that they agree to it.

The slow destruction of privacy is creating situations which have the potential for immense harm for specific people around the world (e.g. people who criticize certain governments). To ignore these sorts of situations whenever there's a discussion on privacy is foolish at best, and maliciously disingenuously at worst.

> I willingly give my personal information over to a variety of firms [...] It's not your place to say whether that's okay or not, because it doesn't affect you.

It absolutely can affect me (or anyone else) if some of that information reveals details about anyone who isn't you. This is exactly the case with (e.g.) all of the social-graph information that Facebook collects. It doesn't matter if someone went through the process of deleting their account if information about them is still being collected by proxy.

That's not to say that any data that could reveal information about someone needs to be treated as though it "belongs" to all parties, but does mean that claiming some form of ownership over the data is not at all straightforward and that merely using the idea of ownership over data is unlikely to address many of the issues that have arisen from mass collection of data on people.

> Human trafficking + consent = immigration.

No. That is entirely wrong. Human trafficking is, by definition, done without informed consent. Stating that just "adding consent to the equation" makes it into immigration is completely ignorant of the motivations, realities and harms of that particularly disgusting criminal enterprise.

The problems with human trafficking don't arise because someone "didn't consent to something"; they arise because of the deliberately-engineered power imbalance between criminal organizations and their victims and the intention of forcing people into indentured servitude and forcing them to make money for the criminals.

> Organ trade + consent = organ donation.

Also no. Organ donation is (or should be) done without any sort of financial benefit to the donor. It's done that way to prevent the organ trade from flourishing. This is exactly the point I was making that assigning a "value" to something doesn't suddenly remove or negate the harms that that thing can cause. In fact, in the case of organ donation, there are a lot of rules which have been set up to explicitly prohibit someone from buying a human organ, specifically because of the known harm that the organ trade does.

> And yes, there should be a practical way to revoke access to data. There are ways to accomplish this technologically [...] We just don't use them yet, for the most part.

There are many ways of collecting aggregate data about populations that don't have to result in individual privacy being destroyed. They aren't used because, under current laws, it's more profitable to just collect all the data and not worry about preventing it from being abused; because there aren't any real penalties for companies and individuals who cause harm by gathering/selling/losing control of this data.

That is to say, it's not (and never has been) a technical issue. It's a political one which requires that people have an informed discussion that isn't heavily swayed by people with a vested interest (e.g. the online advertising industry, as I suspect that many people in this thread are in)