Sometime this past month, a trove of files on the file sharing site MEGA was reported to have been found. This trove was made up of over 12,000 separate files and 87GB of data. These files contained a collection of 2,000 dehashed databases from thousands of websites, some from smaller previously known breaches.
In total, there was 2,692,818,238 rows of emails and passwords with 1,160,253,228 unique combinations of emails and passwords with 772,904,991 of them containing unique email addresses and 21,222,975 unique passwords.
What can be done about this
You can't change the past but you can help prevent yourself from being taken advantage of. haveibeenpwned provides a service where you can lookup your email address to see if your email was affected in a breach listed in their database.
If you find your email listed in a breach, change your email password and all other accounts for other sites that contain the same password. In addition, make sure two-factor authentication is enabled for your email.