NEW YORK – While U.S. troops fight terrorists abroad, law enforcement agents at home use their own high-tech methods to track down potential evildoers.
Precise details of the technologies used by law enforcement are closely guarded, but there's no question the government has steadily developed its own resources, and those of the private sector, to expand the ability to monitor Internet chat rooms and Web activity, wiretap phones and track down cell phone conversations.
"The challenges for law enforcement are just as great, if not greater, in the age of rapidly-evolving technology," FBI spokesman Paul Bresson told Fox News.
Many Americans are already aware of e-mail surveillance programs with names like Carnivore and Magic Lantern. Such programs allow investigators to monitor personal e-mails and electronic communications, but have also been criticized by civil libertarians and privacy advocates for possibly violating individuals' rights.
The Pentagon's Defense Advanced Research Project Agency is also churning out a number of unconventional technologies aimed at improving homeland security. These include bio-surveillance programs that could trace unusual outbreaks of certain diseases, track medication sales and identify terrorist suspects from a distance by focusing on their face and the way they move.
Techies in the private sector are helping. Companies specializing in biometrics, Internet searching, electronic surveillance and other areas have been shopping their wares since Sept. 11 in the hopes the government will use them to help catch terrorists.
For example, Virginia-based Cyveillance crawls through 40 million sites a month in search of suspicious activity, according to Todd Bransford, the company's vice president of product marketing. The company scans the Web for suspicious file-trading activity, downloads and message board notes, which can include topics as varied as bomb-making and anti-American sentiment.
"We download a lot of raw information, then we have technology that processes it for relevancy [and] real intelligence," Bransford said. Government uses "would include everything from information security, identifying the threats and risks that are occurring out there in online discussions."
Protecting the nation’s computer systems themselves is also a priority, according to security experts who fear a coordinated "asymmetric" attack on physical and cyberspace targets.
"We have to take a holistic approach to security these days -- physical security and virtual security are integrated together in our daily lives," said K.J. Kuchta, a cyber-security expert with Virginia-based ASIS International.
Investigators are already using biometrics to identify the voiceprints of telephone conversations. Agents can monitor communication lines for recognized voiceprints to pop up, hopefully identifying wanted terrorists.
However, the terrorists may be tech-savvy as well. They often use encryption programs when communicating over the Internet, scrambling the text of messages as they travel over the Web. Still, they don't necessarily need to be so technologically proficient.
"I see a vast majority of them using just plain old common sense," like using pre-paid cell phones or calling people over the Internet, Kuchta said. "They’re being creative with what they have. It doesn’t take a well-funded, deep pocketed organization to really have some success in hiding their activities."
But not everyone sees the increasing reliance on technology in the war on terror as a good thing.
"We’ve been so gadget-oriented … we give up on the things that are a bit more difficult but are more effective," said Rusty Capps, president of the Centre for Counterintelligence and Security Studies.
Capps said human intelligence is often the best way to get into the mind of terrorists and infiltrate their organizations.
"You’ll always have to have an agent provide you with the intentions of your adversary, while gadgets can give you the capacity," such as how many warheads the enemy may have, Capps said. Without human intelligence, "what you don’t know is when you’re adversary’s going to pull the trigger."