Sanders campaign barred from accessing Democratic voter lists after breach

The Democratic National Committee temporarily barred Vermont Sen. Bernie Sanders' presidential campaign from accessing the DNC's voter file after a software error allowed at least one member of Sanders' staff to look at Hillary Clinton's private campaign information, a spokesman for the campaign said Friday.

Sanders spokesman Michael Briggs told The Associated Press that the campaign had fired a staff member who reviewed the data, but blamed a vendor who runs the DNC's voter database for making "serious errors."

The DNC maintains an extensive list of voter information and rents it out to campaigns, which update it with their own data. The data allows campaigns to target likely voters and anticipate what issues might motivate them to support a candidate.

It remained unclear how long the Sanders campaign would be barred from accessing the DNC data, but the information could be crucial in his campaign's ability to identify and persuade voters in the kickoff February contests of Iowa and New Hampshire. Sanders has built a strong following among young voters and liberals, but Clinton has maintained a lead in the kickoff state of Iowa and in national polls.

The data breach was first reported by The Washington Post.

Firewalls are put in place to prevent campaigns from looking at data maintained by their rivals. But officials said the vendor that runs the system, NGP VAN, used a software patch on Wednesday that allowed all users on the system to briefly access data belonging to other campaigns.

DNC spokesman Luis Miranda said Friday that the party committee "places a high priority on maintaining the security of our system and protecting the data in it."

He said the DNC instructed NGP VAN to conduct an analysis of any users who accessed the data and report back.

The Associated Press