How do you build an online phonebook?

The New York Times recently wrote this piece about PeopleSmart: a web-based company that offers searchable profiles for every citizen of the United States.  

There have been similar services that exist in other web spaces, but PeopleSmart is trying to lend an air of legitimacy to looking up identities online, and it's a challenge--particularly because the action itself is often (though not always)  wrought with suspect intentions.  To allay privacy concerns, the company is withholding search results that could conceivably be used to aid scammers and spammers.  Despite this, you still probably have a very basic profile in their system (I definitely do!)  

It's an interesting project from our 202 perspective, because even without including many details, this is a massive organizational undertaking.  My name, for example, is not a particularly common one, and there are more than fifty returns.  What do you do if you need to locate a Michelle Olson?  Assuming that other pieces of information (such as middle name, location, age, etc.) are not available to the searcher, PeopleSmart provides additional resources, such as possible relatives, along with past locations, to help determine a result.

In order to compile the data, PeopleSoft employed a company called Rapleaf, who probably used web crawlers to glean the essentials from resumes and social networking sites.