unfair?

As a lay man it appears to me that the government's greedy eyes started glowing when they realized how much money was being generated under this tax emeption they provided. So they decided to claim a share of the booty? Looks like rethink on the exemption, unfair and unjust after it has been granted to improve trade and economy.
http://www.deccanherald.com/content/140989/i-t-dept-slaps-rs.html