Slightly off-topic, but if you want to use your Kindle without registering it, but worry that ever connecting to wifi will delete your content and dictionaries and unregister you....
Code:
# mntroot rw
# touch /var/local/system/DONT_DELETE_CONTENT_ON_DEREGISTRATION
# touch /var/local/java/prefs/reginfo 2>/dev/null || chattr -i /var/local/java/prefs/reginfo
# cat <<EOF > /var/local/java/prefs/reginfo
#Mon Jan 01 00:00:00 GMT+00:00 2000
deviceName=kindle
deviceEmailAddress=kindle@pseudo.url
userName=kindle
userId=amzn1.account.XXXXXXXX1A2B3C4YYYYYYYYYYYYY
givenName=kindle
EOF
# chmod 444 /var/local/java/prefs/reginfo
# chattr +i /var/local/java/prefs/reginfo
# grep -q "firs-ta-g7g.amazon.com" /etc/hosts || echo "127.0.0.1 firs-ta-g7g.amazon.com" >> /etc/hosts
# mntroot ro
# restart framework
We just block the domain for registration, so no need to bother with IP ranges in firewalls, etc.
So, the store viewing still works, dictionary lookups, home&library settings, collections, etc.
But Wikipedia and Translation widgets are sadly still unavailable as Amazon require valid credentials to use those proxied services.