An unlisted landline number with Verizon returned full name, carrier, and cost center location within 10 miles. A Sprint cell number gave correct name, carrier

An unlisted landline number with Verizon returned full name, carrier, and cost center location within 10 miles. A Sprint cell number gave correct name, carrier, and city as well. Trying a Google Voice number, though, gives only an unrelated cost center and "Level 3" as the provider. Pretty impressive, overall. Now I can finally figure out all my phone contacts with completely useless names!