We are emailing you because you are a registered user of MacRumors.com Forums. We recently had a security leak in our forums. More details can be found in this blog post:
http://www.macrumors.com/2013/11/12/macrumors-forums-security-leak/
There is a chance that your user data (email address, username, encrypted password) may have been leaked from the site. We recommend you take the following steps:
1. Change your password on MacRumors:
http://forums.macrumors.com/profile.php?do=editpassword
2. If you used the same password on other sites, please change those as well.
Is this email real?
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If you are concerned about the authenticity of this email, please visit forums.macrumors.com on your desktop computer and, and there is a notice at the top of the screen that provides the same information.
Why didn't I get this email sooner?
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We are sending out emails as quickly as we can, but sending out a large number of emails at one time results in most of them being blocked as spam.
Wasn't my password encrypted?
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While the passwords are "hashed" (which is a one-way conversion from your actual password to a scrambled version), given computing power these days, if your password isn't very complex, they could brute force figure it out by trying lots of combinations.
This is a one time email.
We sincerely apologize for the instrusion,
MacRumors.com