LYCOS RETRIEVER 
Credit Card Fraud: Credit Card Numbers
built 647 days ago
There are ... programs that generate valid credit card numbers out of thin air. All valid card numbers end with a "check-sum" digit that's generated from the credit card's other digits, by something called the Mod-10 algorithm.
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Watch closely as store and restaurant employees handle your card to make sure they are not copying or "skimming" your credit card number. The devices used for skimming are sometimes disguised to look like cell phones.
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Always make sure you get your credit card receipt because it just may include your credit card number. Never toss it in a public trash bin. You'll need that receipt later anyway to tally things up when your statement arrives.
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Credit Card Numbers