If you use Firefox/Thunderbird in Mac OS, you still need to untrust the CNNIC certs follow the steps in Screenshot: Remove CNNIC from Firefox and Thunderbird.

In Mac OS X: Click Applications -> Utilities -> Keychain Access -> Certificates -> (expand with V button below) -> System Roots -> (Unlock, top left) -> Double-click the cert -> Trust -> When using this Certificate -> Never Trust.

Instead of removing CNNIC certificates from your system, we should mark them as "untrusted". This way, when your system updates its cerficates, they will not slip in. As a precaution, you might need to form the habit of checking the trusted certficates installed in your system periodically.

Mozilla and Microsoft have added CNNIC root CA to the browser's Authorities and CA directory. Chinese users are in a rush removing them from their computers. Here is a post on how to do it (in Chinese).

Discussions can be found here:

When you compile a program that need to include kernel sources, sometimes the compile might give you an warning message like below:

 *   CONFIG_SYSFS_DEPRECATED:     should not be set. But it is.
 *   CONFIG_SYSFS_DEPRECATED_V2:     should not be set. But it is.

To fix this, you will need to recompile your kernel using menuconfig, and find

When you compile your own kernel, in order to enable support for dm-crypt, please make sure you check

Device Drivers --->
     [*] Multiple devices driver support (RAID and LVM) --->
        <*> Device mapper support
        <*> Crypt target support

Remove MySQL from network

By default, MySQL listens on port 3306. Stop it from listening on any TCP/IP port if you don't use it on network.

# vi /etc/my.cnf

Change
#skip-networking
to
skip-networking

Secure the user accounts

A default install of MySQL is somewhat lacking in security. To fix that we are going to do the following:

Install BIND

# emerge -v bind

When it finishes, here is the message: 

SANS posts daily security tip to remind users on various security aspect. Nice short paragraphs.

http://www.sans.org/tip_of_the_day.php

References:

US-CERT Securing Web Browser Information
http://www.us-cert.gov/reading_room/securing_browser/browser_security.html

• IPTables HOWTO for CentoOS
• How to use iptables against SSH attacks
• Blocking international network traffic to your server 
• How to use IP Tables