This is absolutely 100% true. I know this person and talked to him personally this morning.
He sold some items on craigslist, including a camera. Someone from out of state bought the items. Our friend said he wouldn't ship the items until the check cleared. He deposited the check and was notified by his bank of many years that the check was fraudulent and they'd frozen HIS checking account and IRA with them. It is the bank's policy to freeze all monies if there is fraudulent activity on the account - even though he wasn't the one at fault.
My friend called the person whose name was on the check and found out a person or persons in Nigeria had accomplishes is NY and CA and somehow had stolen a check/identity from a person in Louisiana. The man was getting nearly 100 calls per day from people they'd scammed or were trying to scam.
Bottom line, if you're selling on craigslist - cash and carry only!