Η Have I Been Pwned is a very useful free website that will check if the details of your online accounts have leaked to some of the most recent hacks. The Have I Been Pwned service makes it extremely easy to check whether the email addresses, social networking accounts you use, etc. have been involved in some sort of data breach or not.
All you have to do is provide an account username or email that you use in your online services. The Have I Been Pwned website will immediately cross-check the information and let you know if your account is secure or not.
What is “Pwned”?
In essence, "Pwned" is a mutation of the word "Owned" meaning "Owned".
If you want to see a list of all the websites that have been violated and are available in the service database, you can see them in the section Pwned Sites.
Also the service Notify Mewill notify you of your email when a new violation occurs that contains your information.