I am always amazed as to how foolish some people are when it comes to their personal security, wrt pass codes and credit card details.
However, I was quite gobsmacked to overhear (as did the rest of the carriage) a conversation that someone was having on their mobile phone when travelling to London the other evening.
The lady was buying some tickets for something and happily gave out her credit card details, over the phone, so that the whole carriage could hear them.
It is hardly surprising that there is an epidemic of identity theft and fraud, if people are this cavalier with their security.
Keep your details private!