Courtesy of Payments News, an Interac (payment association) survey that shows most Canadians do not use their debit cards safely.  Here is some sound advice from the association to bank customers who use debit.

• Use your hand or body to shield your PIN when you are conducting transactions at an Automated Banking Machine (ABM) or at the checkout. # Keep your banking card in sight when conducting transactions at the checkout.
• Check your banking statements regularly and contact your financial institution immediately if you detect any unusual activity, e.g. purchases you did not make or missing charges.
• If your debit card is lost, stolen or retained by an ABM, notify your financial institution immediately.
• Memorize your PIN. Only you should know your PIN. If you suspect that someone knows your PIN, even a friend or family member, change it immediately.
• When selecting your PIN, never use obvious information, such as, your telephone number, date of birth, address or Social Insurance Number. These numbers are often stored in the same place as your banking card enabling criminals to easily guess your PIN.

Source: Payments News: Survey Shows Canadians Not Shielding Their Debit Card PIN Regularly – October 19, 2006