An anonymous reader writes from a report via NBC News: Director of National Intelligence James Clapper warned Wednesday that foreign hackers may be targeting the campaigns of U.S. presidential candidates. The FBI and Homeland Security are working with the campaigns to tighten security and prevent cyber intruders from penetrating their defenses, said Clapper. "We have already had some indications of that, and a combination of DHS, FBI are doing what they can to educate both candidates of potential cyber threats," Clapper said, without specifying which candidates they were advising. "I anticipate as the campaigns intensify we will probably have more of it." A senior U.S. intelligence official told NBC News that they are "most worried about Trump, who has no experience with government computer systems or protocols." Foreign hacking against American political candidates is nothing new, Clapper said. Prior to the 2008 presidential election, Chinese cyber spies had targeted the presidential campaigns of then Sen. Obama and Sen. John McCain in order to read emails and policy papers. The hackers successfully compromised some emails, including private correspondence from McCain, NBC News reported. Also, both Obama's and GOP candidate Mitt Romney's campaigns were hit by Chinese cyber-attacks during the 2012 election. The Office of the DNI clarified Clapper's remarks tweeting: "We're aware that campaigns and related organizations and individuals are targeted by actors with a variety of motivations -- from philosophical differences to espionage -- and capabilities -- from defacements to intrusions. We defer to FBI for specific incidents."