As people become more active on social networking sites, social aggregator services which collect information become more powerful. Spread across different sites, a user can and may feel safe sharing certain parts of her life, such as a phone number, email address, or current location, but when collected into one central spot, the level of detail and amount of information available is almost frightening.
This Ars Technica article about password security has numerous examples of leaked passwords hashes (essentially an encrypted version of your website password), both historically and recently--a good example would be the LinkedIn breach in June this year. In this article, the passwords and the hashes they generate are the information being organized.