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In April 2021, a large set of Facebook user data was published on the Internet. The data included information on 533 million Facebook users and included dates of births, email addresses, phone numbers, geographic locations, names, or genders.

Not all of the data was complete, but about 2.5 million accounts had their email addresses leaked along with other data. Malicious actors can use the entire data set to link phone numbers to names, and the subset that contained email addresses for attacks against these accounts, e.g. through phishing emails or brute force hacking.

Have I Been Pwned is a free site on the Internet that feeds an ever growing database with public data leaks so that users from all around the world may search it.

All it takes is to type an email address to find out if it was included in any of the data breaches that the site has in its database.

All you need to do is visit the homepage of the Have I Been Pwned service, type an email address, and click on the pwned? button to run a search for itt in the database.

All hits are listed on the results page. To find out if the email address was included in the Facebook leak, check if Facebook is among the listed services the email address was found in.

Only accounts that included the email address can be searched. The developer of the service, Troy Hunt, mentioned on Twitter that he won't add phone search capabilities to the site because it would be a lot of work and would not provide much value.

What you need to do if your account email has been leaked

The leaked data sets did not include password hashes it appears, but certain forms of attacks are very likely ranging from phishing emails and spam to trying to find the email address or phone number in other breaches, and hacking into accounts.

If the email address has been leaked, it is a good idea to change the password on all sites the email address was used on.

Now You: do you use services like Have I Been Pwned or Firefox Monitor to find out if your data was leaked on the Internet?
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