A hacker has leaked millions of 23andMe user records on a cybercrime forum, following a previous leak of user data two weeks ago. The leaked data includes information on users from Great Britain and the wealthiest individuals in the US and Western Europe. 23andMe has stated that it is reviewing the data to determine its legitimacy. The company had previously announced that hackers had obtained some user data using credential stuffing, a technique where hackers try combinations of usernames and passwords that are already public from other data breaches.