A top US intelligence official has said that a cyber attack on the US banking system could be several times more damaging to the country's economy than twin-tower attack by terrorists on September 11, 2001. "If instead of attacking the Twin Towers al-Qaeda had taken down a major bank, the economic consequences would have been an order of magnitude ten times greater than the economic consequences of 9/11," National Counterintelligence Executive Joel Brenner told a television news channel in an interview. "I don't say the personal physical damage. People were killed in 9/11. But the economic damage of taking down a piece of our banking system would be enormous and it would reverberate through the world financial system," Brenner said. The top US intelligence official said everything that is being done in the US is electronic network. "All the information that we create is created electronically," he said, adding that this makes all the more necessary for making the nation secure from any such type of cyber attack by terrorists.