Hi Thank you for getting in touch with us about this issue, I appreciate that this is very concerning. It may have been the case that you have forgotten your password. If so, please see these [https://support.mozilla.org/en-US/kb/ive-lost-my-firefox-sync-account-information steps] to change it. We have recently become [https://blog.mozilla.org/services/2016/04/09/stolen-passwords-used-to-break-into-firefox-accounts/ aware] that attackers with access to passwords acquired during other data breaches have been using that information to access Firefox Accounts and Sync information. In a number of instances, we have been able to reset passwords, but with a situation like this other accounts may exist that we do not know about. If you believe that your Firefox account is being accessed without your permission, I would strongly recommend that you change your Firefox Account password promptly. You can read more about how to do this [https://support.mozilla.org/en-US/kb/change-your-firefox-accounts-password here]. Other online accounts may have also been compromised. I recommend that you change the passwords (being careful not to repeat passwords for different accounts) and, having done this, update any of these passwords that are stored in Firefox Password Manager. You can read more about how to do this [https://support.mozilla.org/en-US/kb/password-manager-remember-delete-change-and-import#w_viewing-and-deleting-passwords here]. Whilst this issue was largely out of our hands, at Mozilla we want to do everything we can to help you stay safe online. We are working on new features for Firefox Accounts that will further help protect your information.