You generally are not able to view a site because the access control list is configured in a firewall to block any attempts to site and pop-up an error message
The simplest way to overcome is to redirect the traffic – there are more than 1000 proxy servers on the net and they keep increasing everyday (so, no access control list can block all of them – if one is blocked search for other in google )
TRY THESE :
www.breakthefirewall.com
www.zend2.com
www.anonymizer.com
www.jumboproxt.net
www.vtunnel.com
http://www.myipproxylist.com/
They not only allow you to view any site by redirecting the traffic but also help you to carry out hacking .Consider an attack case
UR machine >>> Proxy 1 >>> Proxy 2>>> Proxy3… Proxy n >>> Target Machine
Now the target machine will have ip of last proxy u connected to. SO it will be impossible for them to trace you if u hack them… particularly if all the proxies belong to different countries…
