vote yes on 51. federal and state authorities are now on the lookout for possible russian cyber attacks tied to election day here in the united states. our justice correspondent, pamela brown, has bigging into that. how worried are u.s. officials right now? >> u.s. government officials telling us just today, wolf, that they are very concerned russia will cause mischief on election day by deceiving voters and creating doubt about whether the system is rigds. -- rigged. tonight heightened concerns over russian-led efforts to undermine the u.s. election. u.s. officials warn that hackers could tamper with local databases of voters' names and addresses to cause confusion at the polls. >> we don't know what we don't know. there may be hacking tools and