Our relationship to privacy is inseparable from our idea of trust. If you trust someone, you may be more willing to divulge personal information to them. If you are highly protective of your privacy, you may seem to others to be distrustful.

This is a normal social dynamic. But it is being cynically manipulated by the “sharing” or “trust” economy — where we trade homes, cars or belongings through third-party administrators such as Airbnb — in ways that threaten our privacy.

The chief executive of Airbnb, Brian Chesky, has said that “we don’t think you can be trusted in a place where you’re anonymous.” In order to participate in services like his, Mr. Chesky argues, you need to expose yourself. It’s a model of consumerism that depends on customers’ transparency.

It’s also a model of consumerism that makes our traditional idea of trust irrelevant. To trust someone is to assume that you can rely on them — that they do not need to be monitored or policed. But the infrastructure of the sharing or trust economy is largely a series of technical advances that enable us to track people constantly, removing any need to trust them.