New Scientist reports:

[The] National Security Agency, which specialises in eavesdropping and code-breaking, is funding research into the mass harvesting of the information that people post about themselves on social networks. And it could harness advances in internet technology - specifically the forthcoming “semantic web” championed by the web standards organisation W3C - to combine data from social networking websites with details such as banking, retail and property records, allowing the NSA to build extensive, all-embracing personal profiles of individuals.
[Link]

Via Waxy.org

See also:
AT&T Forwards ALL Internet Traffic Into NSA Says EFF
State Secrets Privilege