My understanding is that the DNC contracts with VAN to manage the voter files for all fifty states. It&#x27;s a shared database, with candidates able to build up their own data on top. All the campaigns can see the underlying voter data, but they additions they make are private to the individual campaign. The Sanders campaign staffers realized they were able to see Clinton campaign data they should not have access to. That&#x27;s all that happened. The problem was fixed within a few hours. The Sanders people didn&#x27;t abuse the bug in any significant way, in fact they reported it. But then the DNC cut off Sanders campaign access completely -- the nation-wide voter file, all their additions, inaccessible. At this point, the DNC response seems more punitive than security-related.