One day in late summer 2008, FBI and Secret Service agents flew to Chicago to inform Barack Obama’s campaign team that its computer system had been hacked. “You’ve got a problem. Somebody’s trying to get inside your systems,” an FBI agent told the team, according to a source familiar with the incident.The McCain campaign was hit with a similar attack.The trail in both cases led to computers in China, said several sources inside and outside government with knowledge of the incidents. In the McCain case, Chinese officials later approached staff members about information that had appeared only in restricted e-mails, according to a person close to the campaign.
http://www.washingtonpost.com/wp-dyn/content/article/2009/11/10/AR2009111017588.html