attacks. officials say such an attack on election day could take down websites voters use for news and information. >> if you shut down or disable or undermine the communications that people are using to figure out where to vote and to actually deal with traffic and things like that, you could create massive delays in lines. >> reporter: u.s. officials say russia has been waging an information operation for months to sow doubts about the vote including e-mail hacks of the democratic national committee. widespread hacking of voting machines in the nation's 9,000 injures dikjurisdictions would task since they're not connected to each other or the internet. officials will be looking for trolling operations, disseminating fake news of vote rigging and tampering. >> it's impossible to hack the election but it's possible for someone to claim it's hacked and to try to influence the public. >> reporter: law enforcement on heightened alert for potential terror attacks around the