What data brokers know about you

Most people picture a data broker as a company holding their email address. The reality is a great deal more detailed. The profile a broker can assemble about an ordinary person is closer to a dossier than a mailing-list entry, and it is built from sources you never directly handed anything to.

What goes into a profile

• Identity: full name, date of birth, current and previous addresses, phone numbers.
• Household: relatives, people you have lived with, marital status.
• Finance: estimated income band, property ownership, indicators of creditworthiness.
• Behaviour: shopping categories, inferred interests, life events such as moving or having a child.
• Location: patterns derived from app and device data that reveal where you go.

Where it comes from

Very little of it is collected from you directly. Brokers combine public records such as electoral rolls and property registries, data bought from apps and websites, loyalty-scheme and purchase histories, and information scraped from the open web. Then they cross-reference all of it, so a gap in one source is filled by another.

Why the cross-referencing matters

A single data point is rarely sensitive on its own. The risk comes from combination. An address plus a daily-movement pattern plus a list of relatives is enough to enable stalking, social-engineering attacks, or targeted fraud. Brokers are in the business of combination, which is precisely what makes the assembled profile worth more than the sum of its parts.

Who buys it

Advertisers and marketers are the obvious customers, but the buyer list is broader: background-check services, debt collectors, insurers, and anyone willing to pay for a people-search lookup. Once your profile is for sale, you have no control over who acquires it or what they do with it.

What you can do about it

You have the right to see what they hold and to have it erased. The practical challenge is scale: the data is spread across dozens of brokers, each with its own process, and it regenerates over time. Knowing what is out there is the first step, and acting on it on a schedule is what actually shrinks the footprint.