Cybersecurity: Continued Attention Needed to Protect Our Nation's Critical Infrastructure and Federal Information Systems, Statement of Gregory C. Wilshusen, Director Information Security Issues, Testimony Before the Subcommittee on Cybersecurity, Infrastructure Protection, and Security Technologies, Committee on Homeland Security, House of Representatives [open pdf - 269KB]
"Pervasive and sustained cyber attacks against the United States continue to pose a potentially devastating impact on federal and nonfederal systems and operations. In February 2011, the Director of National Intelligence testified that, in the past year, there had been a dramatic increase in malicious cyber activity targeting U.S. computers and networks, including a more than tripling of the volume of malicious software since 2009. Recent press reports that computer hackers broke into and stole proprietary information worth millions of dollars from the networks of six U.S. and European energy companies also demonstrate the risk that our nation faces. Such attacks highlight the importance of developing a concerted response to safeguard federal and nonfederal information systems."
Government Accountability Office: http://www.gao.gov