If you're trying to locate an old friend, you might just need to know their current address for a reverse address lookup. Or, maybe you need to do a reverse username search to see who owns the account you found online, or who's been writing to you from a strange email address. No matter the case, you shouldn't pay for a people finder site unless it will most definitely give you information ...
The people search tool funneled publicly accessible information from phone books, white pages, and yellow pages into Yahoo's search service. This information could all have been found on the web and was available to the public at large, meaning that none of it was sensitive, secure, or potentially harmful.