prevent it from happening ever again? >> we want to bring in cnn national security analyst and former assistant secretary of the department of homeland security. julia, what does it mean when we say the white house has been hacked. not just that. we say russia hacked the white house, what do we mean by that and how concerned should we be? >> we should be pretty concerned. there's different systems within the white house both the classified and the unclassified. so what the russians were able to get into was the unclassified. at least that's what we know right now. how they got in, we believe, at this stage is through a back door, which was called the state department. the state department has been suffering a number of what we call phishing expeditions by the russians and penetrated into the white house system. >> some of the information that the hackers were able to access included the president's nonpublic schedule. maybe not classified but clearly still sensitive in knowing the president's movements that aren't released to the public. there's a lot of that.