A moment's carelessness could be all it takes for you to hand a thief a free ticket to a shopping spree on the Internet. A shopping spree that you'll get the bill for.

Police in Charlottetown have charged two adults and two juveniles with using stolen credit card numbers to purchase items on the Internet. And they're warning consumers to be careful with their credit card transaction slips.

"They [the thieves] acquired discarded transaction slips from credit cards," said Cst. Dominique Landry of the RCMP Commercial Crime Division. "From that they acquired the valid credit card numbers, the name of the cardholder, and the expiry date."

More than 60 orders were placed using public-access Internet sites including ones at the Confederation Centre public library in downtown Charlottetown.

The stolen numbers were also used to buy food from local restaurants.

One of the four people charged has pleaded guilty. Police say further charges are pending.

The investigation began in July after victims of the scam spotted unfamiliar purchases on their credit card statements.

Keeping a careful eye on your statement is a key part of preventing credit card fraud, says Landry. "Make sure that your monthly statements are accurate, that the purchases indicated on your statement are the ones that you made personally." But the best way is to make sure thieves can't get their hands on your transaction slip in the first place. "Don't discard it at the local store or outside in the garbage," she said.

Take it home with you. And when you do throw it out, "make sure that it's shredded into little pieces."