HOUSTON -- It is an online haven for drug dealers, pedophiles and even assassins; and many people do not even know it exists.
Nicknamed the underweb or darknet, it is a secret corner of the internet where bad guys can thrive anonymously.
It s been used by people that are trying to run internet scams, to access e-mail accounts, said Ernesto Rojas of Forensics & Security Services Inc.
The only way to get there is by downloading a free program called Tor. It scrambles web addresses into a jumbled series of characters which allow users to do all kinds of things without being caught.
According to its website, Tor was originally developed to protect the U.S. Navy s communications.
But it did not stay secret. Millions of people around the world have grabbed it and used it to cruise the web without a trace.
Tor has been instrumental in allowing people who live in countries with oppressive governments to be able to have access to the free and open internet, Professor Dan Wallach of Rice University said.
Though it has been used for good, some have also used it for pure evil. The outcome has created a nightmare for law enforcement.
Sgt. Gary Spurger is with the Harris County s Precinct 4 Constable s High Tech Crimes Unit, and admits the technology makes it harder to track criminals.
But that does not mean criminals can completely avoid detection by using Tor.
Rojas says there are still ways to track them, especially in instances where money is exchanged.
You can track credit card numbers, you can track other information that allows law enforcement to be able to determine who those people are, Rojas said.
Sgt. Spurger points out criminals also make mistakes.
They re going to present themselves at which point you have your opportunity to take your action, he said. It s just a matter of waiting.
Yet some sites have been thriving for years on the underweb and even the FBI cannot shut them down.
One of the most notorious is The Silk Road, which sells all kinds of illegal narcotics.
Governments have also tried unsuccessfully to shut Tor down, but it appears to be staying.