There are many ways that thieves can steal your information, listed below are a few:
Dumpster Diving: Thieves go through your trash or the trash behind businesses to obtain information.
Skimming: Thieves copy your credit card information by hand or with a machine. This can happen any time that your credit card is out of your sight, such as when paying for a bill at a restaurant. In this case, you can still have your credit card and thieves can still use it.
Phishing: Emails or pop-up adds that request you to provide personal and/or financial information. These often appear to be legitimate emails from a bank.
Unlocked Mailboxes: Also called "red-flagging" - thieves check mailboxes for outgoing or incoming mail that includes checks, credit card offers, etc. Thieves can chemically erase certain inks and fill in the "Pay to the Order of" and amount sections on a check, while leaving a valid signature. Thieves also take credit card offers and open the accounts themselves.
Theft of Wallet, Checkbook, PDA or Computer
Taking Information From Unsecured Internet Websites
Data Collection Devises: High tech theft - keynote loggers, skimmers, and camera phones, computer viruses.
Theft by Family/Friends/Acquaintances
Business Record Theft: Employees stealing or selling customer information.
Fraudulent Calls or Mail: Requesting funds over the phone or in the mail for fraudulent purposes (i.e. false charities).
Change of Address: Mail is misdelivered because of a change or lack of change of an address or thieves change your address.