When the U.S. Department of Homeland Security receives information about potential threats to the U.S., agents may turn to social networking sites like Facebook and Twitter.

Caryn Wagner, undersecretary of the DHS, told an audience Monday at the National Symposium on Homeland Security and Defense in Colorado Springs that the agency began to draw up guidelines for monitoring social networking sites after the sites were heavily used during government uprisings in the Middle East and North Africa this year.

According to an Associated Press report Tuesday, federal agents are still mulling over how to best pull intelligence from social media sites and determine whether it is valid or Web chatter.

"We're still trying to figure out how you use things like Twitter as a source," said Wagner, according to the AP report. "How do you establish trends and how do you then capture that in an intelligence product?"

The DHS, whose mission is to protect the country from terrorist attacks, isn't actively monitoring Facebook or Twitter. However, when the agency receives a tip about a potential threat, agents will scour public sites for information.

According to the report, the DHS is working to set up rules for pulling information from social media sites without infringing on U.S. citizens' privacy.

Dan Olds, an analyst with The Gabriel Consulting Group, said people might be alarmed to learn that the federal government is monitoring social networks, but he isn't surprised.

"Some users might be disturbed, but what would they expect?" Olds asked. "The info they post online is essentially in the public domain in most cases and it's easy to understand why the government would look for any edge they can find vs. terrorists."

What's more surprising than government security agencies monitoring Facebook and Twitter is that they might just be starting to figure it out, Olds added.

"We'd like to hope that government security agencies are ahead of the game when it comes to things like ferreting out useful intelligence from social networking; then we learn that they're probably even with, or maybe a bit behind, businesses on this score," he said. "Corporations, particularly those with consumer products, have been trying to use social networking to understand consumer views and purchasing behavior for quite a while now. While this is still in its infancy, it looks like businesses are a bit ahead of the security agencies on this score."

Zeus Kerravala, an analyst with ZK Research, said that since social networking sites are relatively new, everyone is still trying to figure them out.

"For governments, the challenge is bigger than most," he added. "I imagine they're looking for patterns and codes. The volume of messages is so high that filtering the information is incredibly difficult."

Kerravala noted that it's a good reminder for everyday social network users to be aware that what they post is often available for the public to see.

"You know that a lot of this information is being seen, maybe watched and maybe even archived," he added. "Information doesn't go away once it's posted."

Sharon Gaudin covers the Internet and Web 2.0, emerging technologies, and desktop and laptop chips for Computerworld. Follow Sharon on Twitter at @sgaudin or subscribe to Sharon's RSS feed . Her e-mail address is sgaudin@computerworld.com.