Why is this forum is inaccessible in India?

Well, I was trying to reach this forum and I repeatedly received this message:

Forbidden

You don't have permission to access / on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request. Apache/2.2.21 (Unix) mod_ssl/2.2.21 OpenSSL/0.9.8e-fips-rhel5 mod_bwlimited/1.4 Server at forum.piriform.com Port 80

My ISP appears to be operating from Calcutta/Kolkata, State of Bengal in Eastern India.

Any idea why is that?

Yeah, because you have no choice but to route through Calcutta instead of the UK or US. Are you in Nepal or what?

Ishan also has this issue. It's because the board blocks entire IP Tables, and a lot of indian IP's get caught in the spam filter