Tata Indicom has now applied a fair usage limit of 15GB on the unlimited package offered on their Photon+ Express Wireless Broadband Service.

This service is available in few areas. It promises speeds of up to 3.1 mbps (download).

Update: The limits seem to be different for different region. So, check before you place an order for it.

This image is from the Chennai page:

Checkout: Tata Indicom Express Wireless Broadband Service | Tata Indicom Photon+ Forum