Theres a good chance that someone in konoha knows about madara...most likely its danzo and maybe one or two other advisors.

The thing is, once itachi carreid out his mission to eliminate the uchiha clan, he was probably sent by the higher ups to join the ranks of akatsuki (he could've easily gone into hiding, no need to join the bad guys)....someone in konoha probably knew or suspected that madara was behind the kyuubi attack. They either suspected that he'd be the one running an organization like akatsuki, or at the very least, an organization like that would have some information on him...thats probably why they sent itachi there.

Hell, its even possible that after finishing his mission, he was sent to join akatsuki (since he obviously couldn't return) so konoha would have an inside man on a rogue group, one that had oro as a member. Information is power afterall.