Over a year ago, an anonymous source contacted the Süddeutsche Zeitung (SZ) and submitted encrypted internal documents from Mossack Fonseca, a Panamanian law firm that sells anonymous offshore companies around the world. These shell firms enable their owners to cover up their business dealings, no matter how shady.
In the months that followed, the number of documents continued to grow far beyond the original leak. Ultimately, SZ acquired about 2.6 terabytes of data, making the leak the biggest that journalists had ever worked with. The source wanted neither financial compensation nor anything else in return, apart from a few security measures.