For the investigation, the FBI used search warrants directed at various companies such as Amazon and Google. This showed that the personal information of Anton Napolsky could be linked to Z-Library email addresses and domains in several instances. For example, Napolsky’s personal mail.ru address was used to register zlibdoms@gmail.com, Napolsky7@gmail.com, and feedback.bookos@gmail.com. His personal phone number was also linked to Z-Library email addresses. “Google records reflect that a Russian-based telephone number ending in – 2458 (‘Napolsky Phone-1’) was used to register the email Napolsky7@gmail.com as well as the emails donation.zlib@gmail.com, zlibdoms@gmail.com and feedback.bookos@gmail.com,” the complaint reads. https://torrentfreak.com/how-google-and-amazon-helped-the-fbi-identify-z-librarys-operators-221117/