Over the past week the Indy's received about a dozen postcards thanking us for our recent story on the potential for Montana coal to be exported to Asia. They've come in from the Twin Cities, Milwaukee, Boston and elsewhere. They're thoughtful, hand-written notes signed with only a first name. And the senders all mention an affiliation with Postcard Underground. Google doesn't tell us much about the mysterious group, which only piques our curiosity. Who are these secret admirers? In any case, thanks.