The Spokeo web site defines itself as a "search engine specialized in organizing people-related information from phone books, social networks, marketing lists, business sites, and other public sources." The site combines details available from various publicly available sources online into a single location. For example, it aggregates residence photographs provided by Google Maps with details from various social sites such as Facebook and LinkedIn.
Not surprisingly, some people have privacy concerns about the ready availability of all this personal information in one place. Spokeo makes it possible to opt out of having one's information made available via its Privacy page (there is a link to this on the bottom of Spokeo's main page). The important thing to realize, however, is that Spokeo is just aggregating this information; it's still going to be out there and available even if its reference is removed from Spokeo. This is why I'm surprised when I see people revealing so many personal details online. Once it's out there, you cannot get it back. After all, this is what the people behind the http://pleaserobme.com/ site wanted to remind us.