You know how they always tell you that nobody at your credit card company knows your PIN number? I just got issued a new card by one company, different long number on the front of it for some reason, and they sent out a new PIN too (in a separate letter) as it's a chip+pin card. The PIN number in the new letter, to go with my new card, is my current PIN number.
Now either that was a 1 in 10,000 long shot, or they just re-issued me with my old PIN number on purpose and then posted it to me - which strikes me as a really pointless security risk.