Full Notification

You can sidestep would-be scammers by following these common-sense rules whenever using craigslist:

DEAL LOCALLY WITH FOLKS YOU CAN MEET IN PERSON - follow this one rule and avoid 99% of scam attempts.
NEVER WIRE FUNDS VIA WESTERN UNION, MONEYGRAM or any other wire service - anyone who asks you to do so is likely a scammer.
FAKE CASHIER CHECKS & MONEY ORDERS ARE COMMON, and BANKS WILL CASH THEM AND THEN HOLD YOU RESPONSIBLE when the fake is discovered weeks later.
CRAIGSLIST IS NOT INVOLVED IN ANY TRANSACTION, and does not handle payments, guarantee transactions, provide escrow services, or offer "buyer protection" or "seller certification"
NEVER GIVE OUT FINANCIAL INFORMATION (bank account number, social security number, eBay/PayPal info, etc.)
AVOID DEALS INVOLVING SHIPPING OR ESCROW SERVICES and know that ONLY A SCAMMER WILL "GUARANTEE" YOUR TRANSACTION.
DO NOT RENT HOUSING WITHOUT SEEING THE INTERIOR, OR PURCHASE EXPENSIVE ITEMS SIGHT-UNSEEN - in all likelihood that housing unit is not actually for rent and that cheap item does not exist.
DO NOT SUBMIT TO CREDIT CHECKS OR BACKGROUND CHECKS FOR A JOB OR FOR HOUSING UNTIL YOU HAVE MET THE INTERVIEWER OR LANDLORD/AGENT IN PERSON

http://www.craigslist.org/about/scams