Sunday night was a different kind of “D-Day” — a data day — for 400 journalists, working quietly for the past year digging into 11.5 million leaked documents.

The Panama Papers, an unprecedented release of information from the world’s fourth-largest offshore firm Mossack Fonseca, drew national headlines and comparisons to WikiLeaks. Already, there have been reverberations in the entertainment community and beyond. Jackie Chan is mentioned in the data dump for reportedly holding six offshore accounts. (His representative hasn’t responded to press questions.) Pedro Almodovar and his brother Agustin are also named for setting up an account in the ’90s, and the famous director issued a statement apologizing. As the leaks continue to be made public — especially through a website that is expected to be launched in May that can be easily searched — they could offer a window into the private, and questionable, ways that the rich invest their money.

The information in the Panama Papers was originally offered to the German newspaper Süddeutsche Zeitung, through an anonymous email message. Gradually, the source unloaded millions of emails, PDFs, and photos to the newspaper. Too overwhelming for any one newsroom, the paper passed the documents along to the International Consortium of Investigative Journalists, an organization dedicated to collaborating on investigative stories through a membership network, that until now, has also flown under the radar.

“The Germans decided this was a really big story with names and details that are important for public interest in many, many countries, so they decided they couldn’t do the story justice,” ICIJ reporter Will Fitzgibbon told Variety.

ICIJ, in turn, activated their network of reporters and editors spanning the globe. They made the data available to them through a password-protected hub that can be searched and analyzed. In addition to publishing their own stories, the ICIJ gave the network of reporters complete editorial freedom to dig into the data for a year, insisting only on professionalism and confidentiality for non-newsworthy subjects mentioned in the documents. Eventually they began to negotiate a day that would work for all of the different news organizations to publish, and even decided on the catchy name.

“The importance of the Panama Papers is it shows just how big this parallel world of the off-shore industry is, and how people with a certain amount of political power can more or less choose the rules by which they play,” said Fitzgibbon. “How the off-shore world lets certain people try to pay less in taxes, or to avoid scrutiny of local tax authorities or regulatory agencies in their country. This is something we’ve known exists, but this is by far the most detailed that the world has ever seen about who uses it, why people use it, and the kind of problems in that world.”

Founded in 1997 as part of the Center for Public Integrity, the International Consortium of Investigative Journalists is a nonprofit made up of more than 190 media organizations in over 65 countries, which pays its staff through charitable contributions and public support. (“We’re all hoping the Panama Papers will result in a new stream of small donors,” Fitzgibbon said.) The core ICIJ team is made of six people working in a windowless office in Washington who collaborate with a data team based in Costa Rica, Spain, and Venezuela, mostly through Skype.

They are known for several recent leaks, like the “Swiss Leaks,” that came from inside the HSBC Private Bank in Switzerland that showed client wrongdoing. They also did a recent piece that analyzed World Bank data to show the impact of the bank’s policies, and have covered subjects like tobacco smuggling, private military cartels and climate change lobbyists.

“Some have called us a leak machine,” said Fitzgibbon. “But that’s certainly not what we’re all about.”

Fusion, the cable and digital outlet owned by Univision and Disney, was approached late last year to be one of the reporting partners on the project. Fusion investigative reporter Alice Brennan had worked with the ICIJ in the past. Fusion reporters were given access to the encrypted database to comb through the documents looking for stories that illuminate how tax shelters and shell companies help the 1% shield their fortunes. Part of the commitment to working on the Panama Papers project was an obligation that all reporters share the biggest revelations with the others through the secure social media network dubbed “iHub.” In other words, the mantra was no turf battles over the material — all of the nearly 400 participating reporters were meant to benefit from one another’s legwork, such as the revelations about financial dealings tied to Russian President Vladimir Putin.

“It was a little bit of a free-for-all (in the documents), but nobody has dibs on any story. If someone comes up with the Putin story, anybody can do the Putin story. If you find a lead, you have an obligation to post that link on iHub,” Brennan told Variety. “Collaborating with other media organizations has been very, very fruitful for us.”

The fact that word of the document dump did not leak out into other media is a testament to the dedication and principles of the participating journalists, added Keith Summa, exec producer of Fusion’s investigative series “The Naked Truth.” Fusion will air an hourlong documentary on the Panama Papers reporting process on April 17. It also posted numerous stories on its website on Sunday and Monday.

Recruiting so many reporting partners was key to supporting the effort. News orgs contributed the time and resources of staffers, otherwise the ICIJ and Suddeutche Zeitung could never have afforded to mount the more than year-long investigation.

“These projects are challenging. Not a lot of journalism organizations have the luxury of the resources that we have,” Summa said. Two decades ago, Summa was involved in researching the documents in the famed Brown & Williamson whistleblower case that exposed the dirty secrets of the tobacco industry.

“This to me trumps all of that,” he said. “People will be looking at these documents for 2o to 30 years as a way to understand how people engage in these kind of actions, from sleazy drug lords to heads of state.”

Reporters were working under strictly top secret circumstances until mid-March, when the ICIJ lifted the embargo on reaching out to other sources and those implicated in the documents. At that time, a dozen TV news crews from outlets around the world descended on Panama to seek comment from Mossack Fonseca. The shock of so many reporters coming forward at the same time forced the company to respond.

“It was only because there were 12 TV stations knocking on the door at the same time that we got them to respond,” Brennan said.

The ICIJ’s advisers include Bill Kovach, former head of the Nieman Foundation for Journalism at Harvard University, who spent 18 years at the New York Times; and Charles Lewis, founder of the Center for Public Integrity, who worked at ABC and CBS for 15 years; the advisers are directed by Gerard Ryle, who spent two decades as a reporter, investigative journalist, and editor at the Sydney Morning Herald.

“A leak this size could not have been analyzed or hosted by computers until very recently, let alone made searchable, shareable and made available to journalists from Iceland to Kenya,” Fitzgibbon said. “But being able to allow 400 journalists to communicate certainly takes us far and beyond the world of email.”

Cynthia Littleton contributed to this story.