Have I been pwned? is a service by Troy Hunt that keeps a list of all publicly leaked breaches and allows you to enter your email and see if you’ve been pwned.
Then it’ll tell each breach your email has been involved in. This is great for then running an audit against your password to make sure you didn’t reuse the one with a pwned service on other sites. (You are using different passwords for each account, right? If not, start today.)
The site also offers a “Notify Me” feature that will automatically email you anytime a new breach is discovered with your email in it. I received an email this morning from this and it reminded me how useful this service really is. If you haven’t signed up for that it’s worth doing.