They paste the identity details provided by the passenger in front of the compartment. When PAN number is given as ID by a passenger, the information pasted on the compartment is copied by some fraudulent antisocial people. The PAN no. and other details of the passenger are used to purchase gold above 2lakh Rupees, where PAN no. is warranted. This will attract the attention of tax department towards a person, who has not purchased, and is being victimised.
Identity fraud is so easy in India. With just a electric / mobile bill n pan card..you can change address's n take loans n credit cards.
Most of the Indians are not even aware of the credit reporting agency CIBIL that tracks your history.
Be careful of your documents.
This has to be brought to the notice of concerned authorities.