Kurt "CyberGuy" Knutsson explains how to look up a phone number for free after seeing an unknown caller dialing you, and shares the specific services you can use.

A reverse phone lookup can reveal the name and address associated with a phone number. But beware of websites asking for your personal information.

While it’s impossible to find someone’s social security number by name for free online, you can use someone’s name to find other important information about them.