An electronic rights advocacy group is expressing concern over what it contends was an overly broad surveillance of social networking sites conducted by the U.S. Department of Homeland Security in the days leading up to the 2009 inauguration of President Barack Obama.

The Electronic Frontier Foundation (EFF) recently obtained documents pertaining to the DHS's monitoring of social networking sites through a Freedom of Information Act (FOIA) lawsuit.

The documents show that the DHS established a unit called the Social Network Monitoring Center (SNMC) last year to scour social sites for signs of potential security threats during the presidential inauguration.

The sites targeted by the SNMC included predictable ones such as Facebook, Twitter and MySpace, in addition to more demographically focused sites such as MiGente and BlackPlanet.

The SNMC's other surveillance targets included news sites such as NPR, CNN's iReport and DailyKos, a site that specializes in political commentary.

Throughout the inauguration period, the SNMC was tasked with looking for "items of interest" in posts pertaining to events, organizations and activities. The SNMC was to then conduct an analysis of the data it gathered and create a summary and exception report based on observed trends over a 24-hour period.