Reuters reports: The U.S. government is expanding a cybersecurity program that scans Internet traffic headed into and out of defense contractors to include far more of the country’s private, civilian-run infrastructure.

As a result, more private sector employees than ever before, including those at big banks, utilities and key transportation companies, will have their emails and Web surfing scanned as a precaution against cyber attacks.

Under last month’s White House executive order on cybersecurity, the scans will be driven by classified information provided by U.S. intelligence agencies – including data from the National Security Agency (NSA) – on new or especially serious espionage threats and other hacking attempts. U.S. spy chiefs said on March 12 that cyber attacks have supplanted terrorism as the top threat to the country.

The Department of Homeland Security will gather the secret data and pass it to a small group of telecommunication companies and cybersecurity providers that have employees holding security clearances, government and industry officials said. Those companies will then offer to process email and other Internet transmissions for critical infrastructure customers that choose to participate in the program.