For those of you interested in security I have a guide
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for Arno's Iptables Firewall with a Port Scan Attack Detector (
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) &
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. Also another guide
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for running a Host Intrusion Detection System (
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) with an SSL web user interface.

With these installed your system will email you when your system is scanned (& automatically block the offending IP's) & also if any system files change (usually this should be when you do a dist-upgrade). OSSEC also scans for rootkits.