Update, 1:55 p.m.: Sanders campaign manager Jeff Weaver said minutes ago at a press conference in Washington, D.C. that the DNC has "stolen" the campaign's data by freezing its access to the NGP VAN database and that the campaign will file a suit in federal court this afternoon if its access is not restored. The DNC, Weaver says, is "actively attempting to undermine" Sanders through its actions; Weaver also said Sanders' data was "lost to one of the other campaigns" during an earlier breach. Fired staffer Josh Uretsky, speaking on MSNBC, said the earlier breach Weaver was referring to involved a different system than the one involved in the current scandal. Neither Weaver or Uretsky cited specific evidence that another campaign had taken Sanders' data.
Bloomberg, meanwhile, reports that Sanders staffers "created at least 24 lists" of Clinton data during Wednesday's breach and "saved those lists to their personal folders." This would seem to contradict an earlier statement made by NGP VAN.
Original post, 10:44 a.m.: The Democratic National Committee has temporarily suspended the Bernie Sanders campaign's access to a DNC-operated voter data system after Sanders' national data director accessed proprietary data belonging to the Hillary Clinton campaign during a security failure; the staffer in question, Josh Uretsky, has been fired. A total of four Sanders staffers reportedly accessed Clinton data, but the Sanders campaign said three of them did so at Uretsky's behest and that no Clinton information was ever downloaded or printed. Bloomberg Politics reports that, per the company that operates the database that was breached, the glitch that allowed the improper access did not allow Sanders staffers to "export, save, or act on" Clinton data.
Uretsky told CNN that he was not trying to steal information but to ascertain the extent of the Sanders campaign's own vulnerability after noticing a firewall failure in the system, which both campaigns use to analyze DNC voter information:
"We knew there was a security breach in the data, and we were just trying to understand it and what was happening," said Josh Uretsky, reached by phone on Friday morning, a day after the campaign let him go.
He added, "To the best of my knowledge, nobody took anything that would have given the (Sanders) campaign any benefit."
The vendor that operates the system, NGP VAN, told the Washington Post that firewalls protecting the campaigns' proprietary uses of the voter info went down during the application of a software patch. The DNC says the Sanders campaign will not be allowed access to the system until it gives the DNC a full account of its actions during the breach "as well as assurances that all Clinton data has been destroyed," though given Bloomberg Politics' reporting and Sanders' statement it does not seem likely that a significant amount of data was taken.