In the last months of 2017, the news cycle around the world was dominated by reports of tax neutralization by the rich and powerful. This was the result of a thorough analysis by news outlets of 13.4 million leaked documents that detailed the taxavoidance strategies of wealthy individuals and companies. The leaked documents, in large part originating from tax consultancy firm Appleby, were dubbed the "Paradise Papers" after the idyllic islands that had served as tax havens, such as Bermuda, where Appleby's headquarters are based.

These documents came into the possession of the German newspaper Sddeutsche Zeitung, whose managers quickly realized that they would be unable to analyze all the data by themselves. They reached out to other news organizations, including The Guardian and the BBC in the United Kingdom. No one knows for certain how many journalists and data analysts combed through the emails, reports, and accounts weighing in at over I ,400 gigabytesthere were likely hundreds of them. But all their efforts proved worthwhile, yielding a long list of scoops.

The star of the Irish band U2, Bono, turned out to be part owner of a shopping center in Lithuania that was being investigated for dodging taxes. A member of the British House of Lords, Baron Ashcroft, proved to have retained residency status outside the United Kingdom to evade taxes despite his protestations that he was a UK resident. The list of revelations went on. Most of those named in the Paradise Papers denied the accusations or stated that the tax neutralization methods they used were perfectly legal. Bono claimed ignorance ofthe shopping mall in Lithuania and said that he welcomed the insights provided by the analysis of the Paradise Papers.

The Paradise Papers reports were a triumph of what has come to be known as big data journalism. Few readers recognized what a major feat it had been, not least because the methods used were closely guarded. The International Consortium of Investigative Journalists, which played a major role in coordinating the analysis of the data, recognized that computer scientists would have to play a vital role in this enterprise. A chief technology officer was appointed to supervise the efforts along with six software developers. Access to the files was restricted; for one thing, the identity of the whistleblower had to be protected. At the instigation of the Consortium, all systems used by the journalists while studying the files were encrypted and a two-factor authentication system was applied. Many journalists were not well versed in security issues and had to be taught before they could work on the documents.

Not only did the leaked documents number in the millions, but they came in various formats toosome of these files were even in PSP (Paint Shop Pro). One reason for this was that Appleby was not the only source of the documents; in total, there were at least 19 data sources. A big challenge, thus, was devising a system that allowed easy access to all the files. However, the documents included emails, handwritten notes, photos, etc.files that could not be read by machines, an absolutely necessary precondition for establishing a database.

A software company named Nuix stepped in and assisted in transforming all of these documents into a readable format through advanced optical character recognition software that could recognize text based on combinations of words that often occur together. Ingenious solutions like this allowed the journalists to finally put all the files in one database. Data analysts then devised algorithms that could cut across the many coding systems used in the 13.4 million documents and create links between companies and individuals and the data relevant to them.

This was perhaps the most difficult part of the enterprise, as it required close cooperation between the computer scientists and the journalists. To create a successful and efficient algorithm, the journalists needed to provide the data specialists with lists of the terms that were used in the Paradise Papers to refer to individuals and companies. As there are many of theseand they sometimes appear only as numerical codesthere was a strong need for cooperation between the journalists on the one hand and the data analysts on the other. Generally speaking, the success of big data journalism is contingent on close cooperation between data analysts and journalists; the challenge for journalists is to provide the data experts with clear information, while the challenge for the data experts is to create a knowledge center that journalists, many of whom are decidedly not computer wizards, can easily use.

The reporting on the Paradise Papers has been universally acclaimed as an outstanding example of how new technology and techniques can be used to journalism's advantage. The news outlets won many awards for their work, including a prestigious Investigative Reporters and Editors award recognizing the innovative use of big data. 1. Why was it a challenge to place all the documents from the Paradise Papers in one database?

2. Protecting the identity of a whistleblower or whistleblowers is of vital importance to journalists. Give at least one reason why this is so important.