Yes it is. I just stick all blacklists in a single file of /etc/modprobe.d/blacklist.conf.
https://wiki.archlinux.org/index.php/Si … l_firewallThe reason why the internet still worked was because the linux firewall is stateful. See the above article to get an understanding of what that means.
@cfr, you know you can simply use [[ -f /etc/profile ]] && . /etc/profile instead of the if/then statement. It will work either way, but I use the one liner because it makes my .xinitrc look a little cleaner.