Market-insight companies and people search sites tend to work in a similar way. They gather information from publicly-available sources like electoral registers and property records, then make this data (or conclusions drawn from it) accessible for a fee.
Unfortunately, this practice is completely legal. There are laws against using this information to determine a person’s eligibility for employment, scholarships, or government benefits but you’d never know if this occurred.
Additionally, CoreLogic is allowed to share your data with more or less any company it wants. The only way to actually learn who has access to your information is to request disclosure, and this is only an option if you live in California. Even then, CoreLogic only responds to one of your requests per year).