haveibeenpwned.com
See if your personal email is in the open
Just about every week you hear about a major database breach where hackers are stealing personal data.
A couple of years ago, Troy Hunt put together a website to see if your email address has been compromised in a data breach. Making it easy to see if your "personal" email is accessible to hackers.
Website Description
This site came about after what was, at the time, the largest ever single breach of customer accounts ' Adobe. I often did a post-breach analysis of user credentials and kept finding the same accounts exposed over and over again, often with the same passwords which then put the victims at further risk of their other accounts being compromised.
The FAQs page goes into a lot more detail, but all the data on this site comes from "breaches" where data is exposed to persons that should not have been able to view it.
Why Check Your Email?
If you use your personal email for logins, then it might be useful to check the database. Especially if you use the same password through most accounts.
I checked some old work emails, and I was surprised they were in the database. I know that it doesn't belong to anyone else because the company isn't in business anymore.