The line is an output from the iptables or also know as your firewall.
The logs are sent to the /dev/console when they pop up becuase more that likely in your /etc/syslogd.conf contains something like this.
To stop it you will need to stop the syslogd daemon. normally in redhat/fc* I use the command minus the ' ' as ' service syslogd stop '. Now as root edit /etc/syslogd and add a ' # ' infront of the line and save it. Example
Or one could change the level of kern to say kern.error. Example
Reason is most iptables defualt logging level is usually kern.warning some times kern.notice which are both lower level signals. This can be defined in the firewall script. So what will happen now is there will only be a display like above from apps sending to the kern at error or higher level.
This is the what kern levels are with the first being least important to top priorty. kern.debug, kern.info, kern.notice, kern.warning, kern.error, kern.crit, kern.alert, kern.panic.
Now what will happen if a siganl is sent as kern.warning or lower it will not be displayed. So if there one sent in the lower range you will not see it.
Once edited restart syslogd ' service syslogd start '.
If you wish not to mess with that and you know where your iptables script is then remove the -j LOG at the end of the lines.
Hope this helps