As per the new order of Reserve Bank of India, From December 1st 2013 onwards, People who are shopping with Debit card must enter the 4 digit PIN number on the swiping terminal in order to make the payment.
Here is a true story, one of my friend went to Delhi for a project work. One day someone stolen his wallet and when he tried to call the bank to block the card the phone turned off due to battery low really a bad day for him. He rushed to his room and charge up the phone to make call. Once he turned on the phone. He got 5 transactional message say's that around 20,000 Rs. was taken from his account for shopping. So the thief took the card and made a purchase by swiping the card without entering the PIN.
So from now onwards such kind of tricks is not going to work. When ever you you shop with your Debit or Credit card you have to enter PIN to complete the transaction process.
This is a good initiative by Reserve Bank of India for better, safe, and secure shopping with Debit/Credit Cards. This is also applicable for On-line shopping also.