Both Bazzell and Giglio point to dating addresses and websites as useful ways of tracking someone down online. The likes of Prophet, ContactOut and Discoverly can help you turn a little bit of information into a lot free? try installing any of these hookup add-ons and see the difference it makes as you look up people without Facebook, Twitter, LinkedIn, and elsewhere. All those browser extensions designed to make it easier to do some professional networking, by showing you contact info that is often hidden, can also be mined for information as well.