WeLeakData.com was a hacker forum and marketplace that primarily focused on discussing, trading, and selling databases stolen during data breaches and combolists that are used in credential stuffing attacks. At the end of April, the site mysteriously shut down and rumors began circulating that the operator may have been arrested and that the forum database had been stolen or sold to another member. Threat actors have been posting to underground criminal forums asking to purchase the leaked database. Cyble has added the information from this database to its data breach lookup service so that users can check if their information was leaked.
Source: https://www.bleepingcomputer.com/news/security/hackers-private-chats-leaked-in-stolen-weleakdata-database/