Senator Bernie Sanders' presidential campaign is threatening to take the Democratic National Committee to court after the Committee suspended the campaign's access to valuable voter data. The DNC accuses the campaign of exploiting a technical breach to obtain information collected by Hillary Clinton's campaign.

The data breach was discovered Wednesday by the Democratic party's voter data software vendor, NGP VAN. The glitch broke down the firewall between the Sanders campaign and Clinton operation. According to The Washington Post, at least four Sanders staffers took advantage, briefly viewing data the Clinton campaign had collected.

As a reprimand, the DNC has cut the Sanders campaign off from its voter list until it can prove that any data that was accessed inappropriately has been disposed of, and a thorough audit has been conducted by NGP VAN.

"We are working with our campaigns and the vendor to have full clarity on the extent of the breach, ensure that this isolated incident does not happen again, and to enable our campaigns to continue engaging voters on the issues that matter most to them and their families," said DNC spokesperson Luis Miranda in a statement.

The Sanders campaign, however, is framing this as an "unprecedented" overreaction by the Democratic party and an effort to give Clinton's campaign an unfair advantage. "By their action, the leadership of the Democratic National Committee is now actively attempting to undermine our campaign," campaign manager Jeff Weaver told reporters outside the campaign's Washington DC headquarters. "This is unacceptable. Individual leaders of the DNC can support Hillary Clinton in any way they want, but they are not going to sabotage our campaign - one of the strongest grassroots campaigns in modern history."

Weaver said this was not the first time that such a breach has occurred. He said that two months ago, the Sanders campaign discovered another glitch that caused the firewall between campaigns to break down and notified the DNC about it. NGP VAN CEO Stu Trevelyan denies the company ever received word of that breach, however, and the DNC has not yet responded to WIRED's request for comment on it.

The Sanders campaign has already fired its data chief Josh Uretsky, who was among those who looked at the data. In an interview with CNN, Uretsky said his team was "just trying to understand it and what was happening."

"To the best of my knowledge," he said, "nobody took anything that would have given the (Sanders) campaign any benefit."

For now, however, the Sanders campaign is at a standstill, unable, Weaver says, to even generate phone numbers of potential donors and voters. Weaver stressed the fact that much of the data being withheld is data that the campaign's own volunteers collected and that its own donors supplied. "It's impossible to mobilize the kind of grassroots campaign we have without access to that data," he said.

Weaver also said that "[I]f the DNC continues to hold our data hostage, and continues to try to attack the heart and soul of our campaign, we will be in federal court this afternoon seeking an immediate injunction."

Such a move may sound drastic, but it reflects just how a huge a problem this could be for Sanders. The Iowa Caucus, the first electoral event of the campaign season, is less than two months away. The New Hampshire primary takes place shortly after that. One-to-one communication with voters in key districts is more crucial than ever, and these voter data files are the only way for campaigns and volunteers to know which voters to target.

While the breach is, no doubt, troublesome for the Sanders campaign, it's equally scary for the party as a whole. NGP VAN is the lifeblood of Democratic campaigns. It has been building tools to manage the entire party's data for nearly two decades, a consolidation of information that has become a major strategic advantage for Democrats. A technical glitch like this reveals the risks associated with entrusting all that sensitive data to just one vendor.

According to a blog post written by Trevelyan, shortly after the breach was fixed, the company audited its system and determined that only the Sanders campaign, and no other outside parties, could have possibly retained any of the exposed data. On Thursday, the DNC requested that NGP VAN suspend the Sanders campaign's access to its records. "We will continue to work with and report to the DNC regarding this issue to ensure that this isolated incident does not recur," Trevelyan wrote. "We have and will do better."

That won't, however, do much to help the Sanders campaign. At this point, it's unclear how or when it will regain access to the data. The DNC is even considering contracting an independent security firm to conduct an audit, a move that could further delay the campaign's access to the voter file. Meanwhile, Weaver says the campaign is carefully combing through staff emails, Google Docs, even emails that were deleted at the time of the glitch to find out who was implicated and ensure no records have been retained. While Weaver laid much of the blame on the party and on NGP VAN, he acknowledged that the staff was wrong to look at the information in the first place.

"In the heat of these campaigns," he said, "sometimes young people make misjudgments."