If Russia is found to be behind the Democratic National Committee hack and subsequent leaks of information, that infiltration would represent a paradigm shift in cyberwarfare, security experts say.
"There's been a line that has been crossed, and there has to be some type of response if, indeed, there is a nation-state responsible," said Chris Finan, a former White House cybersecurity director in the Obama administration.
On Friday, WikiLeaks released some 19,000 DNC emails and attachments — the latest in a series of releases of sensitive information stolen from hacked DNC servers, and released in the run-up to the U.S. presidential election.
Several weeks ago, Russian hackers were reported to have breached the DNC's servers, but WikiLeaks has refused to disclose where it obtained the information, which seems to show party leaders favoring Hillary Clinton, now the presumptive nominee, over Vermont Sen. Bernie Sanders.
"You can't let it go unaddressed, because otherwise you are leaving our political institutions vulnerable to this type of intrusion in the future," said Finan, who is now the CEO of data security firm Manifold.