Are they blocking by IP or just DNS? Are you guys typing just domain names, or are you trying the IP addresses too?
Add a line to your HOSTS file and see what happens:
74.113.233.128 vimeo.com www.vimeo.com
curl -v -H "Host: thepiratebay.se" http://www.google.com/It's not surprising, because a year or so ago Airtel was using deep packet inspection to throttle torrents and file sharing sites. They already have the necessary equipment in place, they can use it when and as they please.