If you fork git repos, make sure to pull them down, if the official repo is taken down, your forks will disappear unless you have a copy.

Here's a script I made to backup all your repos, throw it into a cron and run once a month or something, where 20 is the largest number of pages you have, adjust accordingly. I actually wrote this up when a fork I had disappeared.

   #!/bin/bash
   USERNAME='segmond'
   for i in `seq 1 20`;
   do
        curl --fail -s https://api.github.com/users/$USERNAME/repos?page=$i | jq '.[] | .clone_url' | xargs -t -n1 git clone
        sleep 1
   done