(CBS News) The Senate debated a bill on Wednesday to improve America's cyber security. The Department of Homeland Security said we've seen a 20-fold increase in computer attacks recently. So how vulnerable are we?
After 24 years with the FBI -- many spent as the bureau's top cyber cop -- Shawn Henry has come face to face with the Internet threat. And he's worried.
"I think that it is very, very likely," said Henry when asked if a serious cyber attack against critical system in the U.S is inevitable. "I'm quite frankly surprised it hasn't happened yet."
Every day, U.S. government and private computer systems are being probed by cyber thieves and state-sponsored hackers from China and Russia.
"There are estimates that there are attempted breaches in the millions of times per day. They'll just continuously knock until they find an edge to get in," Henry said. Asked whether they have gotten in, Henry replied: "They get in regularly."
In 2011, Henry led the FBI in breaking up an international hacker ring that had infiltrated 4 million computers, including some at the U.S. space agency NASA.
The head of the U.S. Cyber Command estimates corporate and government losses may already total $1 trillion. Many companies don't even know they have been hacked.
"When I was with the FBI," said Henry, "our agents routinely went out and knocked on the doors of major companies and told them that their networks had been breached. And the reason we knew their networks had been breached was because we found their data outside their network in the course of another investigation."
Sen. Joe Lieberman is behind the new bill aimed at tightening cyber defenses. Of the grim overall picture that government analysts have painted, Lieberman said: "Well, the picture is dangerous. Somebody can attack us through cyberspace and really do as much or more damage than the terrorists did on 9/11, by knocking out the power grid for weeks, by incapacitating all of our banks."
Lieberman's bill seeks to protect those critical networks by encouraging companies to share sensitive threat information and requiring them to report all attacks.
"I think out time is running short," said Henry. "And I think it's important that people take this seriously today. We can't wait for the physical implication."
Despite those dire warnings, some businesses still oppose the new cyber bill, calling it more unnecessary government regulation. And vote counters said Lieberman may not have the political muscle he needs right now to push the measure through.