In the banking space, there's this thing called Do Not Call register (akin to a do-not-disturb board put outside the hotel rooms) that each bank has to maintain, as regulated by Reserve Bank of India. Any one who wishes not to receive those marketing cold calls from a particular bank has to enrol his/her name in this register. After doing this, the cold calls are not supposed to bother you again (though it has not worked in case of a couple of banks I tried with). One can complain to the regulator if he/she continues to receive these calls after getting them enrolled (yet to try this).
Today's Economic Times reports that this service is being mis-used by customers (borrowers) who get calls from the bank asking them to repay the loan!
Now, isn't that smart! :)