It is a common assumption that to find out about a person, one must begin with a great deal. In fact serious enquiry usually begins with very little: a name, perhaps, or an address, or a single account. What matters is not how much one starts with but that the starting point is firm. From one fixed detail, a surprising amount can be reached.

The reason is that records are connected, and a connection can be travelled in either direction. A detail that identifies a person in one record will identify them in another that shares it. That second record contains further details, each of which is a new starting point of its own. The process is not a single leap from ignorance to knowledge. It is a series of small, ordinary steps, each one drawing on the last.

Consider how it proceeds. A name leads to an address. The address leads to a record of property, which carries a date and a price and perhaps a company. The company leads to a filing, which names other people and other interests. Each of those is a thread that can be pulled. Nothing in the sequence is dramatic. Each step is the sort of look that anyone might take. It is the accumulation that produces the result.

What makes a single detail powerful, then, is not the detail itself but its position. A detail that connects to nothing is inert. A detail that sits at the centre of many records is a doorway, and most of the details by which a person is ordinarily identified are doorways of exactly this kind. They were never meant to be secret. They were meant to identify, and identifying is precisely what allows them to open a life.

This is worth understanding because it corrects a natural mistake. People tend to guard the facts that feel sensitive and treat the identifying details, the name, the address, the number, as harmless because they are not themselves embarrassing. But it is the identifying details that do the opening. The sensitive facts are simply what is found once a door has been used.

To assess one's own exposure honestly, then, is to ask not what is hidden but where an enquirer would begin, and what the first door would lead to. The answer is usually further than expected, because a life is more connected than it feels from the inside, and a single detail is rarely just a single detail.