Jim just told me about something that happened to one of his coworkers...
She used her credit/debit card to purchase gas at the pump (like most of us do).
She received her receipt like normal. However, when she checked her statement,
there  were 2 $50 charges added in addition to her purchase. Upon investigation,
she found out that because she did not  press the 'clear' button on the pump,
the  employee inside the store was able to use her card to purchase his/her own
gas!

To keep this from happening, after you get your receipt, you must press the
'CLEAR' button or your information will be stored until the next customer
inserts their card. Be sure to tell all your friends/family so that this
doesn't happen to them!