Kate Knibbs reports in Wired magazine:

Against the company’s wishes, a court unredacted information alleging that Meta used Library Genesis (LibGen), a notorious so-called shadow library of pirated books that originated in Russia, to help train its generative AI language models. [...] In his order, Chhabria referenced an internal quote from a Meta employee, included in the documents, in which they speculated, “If there is media coverage suggesting we have used a dataset we know to be pirated, such as LibGen, this may undermine our negotiating position with regulators on these issues.” [...] These newly unredacted documents reveal exchanges between Meta employees unearthed in the discovery process, like a Meta engineer telling a colleague that they hesitated to access LibGen data because “torrenting from a [Meta-owned] corporate laptop doesn’t feel right 😃”. They also allege that internal discussions about using LibGen data were escalated to Meta CEO Mark Zuckerberg (referred to as "MZ" in the memo handed over during discovery) and that Meta's AI team was "approved to use" the pirated material.