ATM Hacking..how they did it with old machines.

hi,
i like to share a news report which tells us how some hackers hacked an old generation ATM machine..
It is said that they entered into machine software and changed the value that machine identify...Thus the machine will start to identify rupees 500 for 100 or the way they set it..
So after they do this, when they withdraw money..say 500 rupees..instead of five 100 notes to come out, five 500 notes will come..Here in the records the person has only withdrawn 500 rupees..but the machines actually gave him 2500 rupees.
cool right..I

If you know such type of stories..do share.