Block site host squid

http://askubuntu.com/questions/180941/blocking-multiple-sites-with-etc-hosts
http://jaxov.com/2009/09/how-to-block-websites-in-ubuntu-linux/

hosts example

127.0.0.1 localhost
192.168.1.199 UbuntuServer
0.0.0.0 r.twimg.com
0.0.0.0 p.twitter.com
0.0.0.0 cdn.api.twitter.com
0.0.0.0 static.ak.facebook.com
0.0.0.0 s-static.ak.facebook.com
#0.0.0.0 i.yimg.jp
0.0.0.0 auction.c.yimg.jp
0.0.0.0 auctions.yahooapis.jp
0.0.0.0 connect.facebook.net

# The following lines are desirable for IPv6 capable hosts

1 ip6-localhost ip6-loopback

fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters