Even without using a paid service, if you know what state someone lives in and can narrow it down to a few potential counties, it's typically not that hard to f

Even without using a paid service, if you know what state someone lives in and can narrow it down to a few potential counties, it's typically not that hard to find someone's address by searching online property tax assessment records which usually expose the full address of the property, the owner's name, and the assessed value. Same for court/criminal records, marriage records (in some states), etc.