Using Maverick, I modified my hosts file to deny access to facebook, doesn't work as intended

Question

I modified both /etc/hosts and /private/etc/hosts here it is

##
# Host Database
#
# localhost is used to configure the loopback interface
# when the system is booting.  Do not change this entry.
##
127.0.0.1   localhost
255.255.255.255 broadcasthost
::1             localhost 
fe80::1%lo0 localhost
0.0.0.0 www.facebook.com
0.0.0.0 facebook.com
0.0.0.0 login.facebook.com
0.0.0.0 www.login.facebook.com
0.0.0.0 fbcdn.net
0.0.0.0 www.fbcdn.net
0.0.0.0 fbcdn.com
0.0.0.0 www.fbcdn.com
0.0.0.0 static.ak.fbcdn.net
0.0.0.0 static.ak.connect.facebook.com
0.0.0.0 connect.facebook.net
0.0.0.0 www.connect.facebook.net
0.0.0.0 apps.facebook.com

Apparently firefox still can connect to facebook, but apparently a ping facebook.com times out as expected. I even restarted firefox without success.

I've also ran

dscacheutil -flushcache;sudo killall -HUP mDNSResponder

Any idea ?