Email addresses and passwords captured
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The CERT-RU has sent a warning mail to the 600 ru.nl mail addresses that were in the list of 1.3 million captured Dutch accounts. That ru.nl mail address has apparently been used as a registration address in some website, that has been hacked. You must assume that passwords that have been used in such a hacked site are now known to Internet criminals. Therefore, you should never use that password anywhere again. Furthermore, everyone is advised to use different passwords for different websites/applications. Often you do not even have to remember these passwords, as they can be easily reset. In other cases, you can use a password vault such as KeePass, which is available for Windows, Apple, Android and Linux.