Linux : How to fully block adsense adds on your system

The method uses IPtables to accomplish this

add the following lines to /etc/rc.local

iptables -F
iptables -A INPUT -s googleads.g.doubleclick.net -j DROP
iptables -A INPUT -s pagead2.googlesyndication.com -j DROP
iptables -A INPUT -s ads.google.com -j DROP
exit 0

Thanks : Tux