According to the survey by Bank of  America,  18% of Americans said they have withdrawn retirement assets prematurely because of the recent economic turmoil. Many raided those accounts to pay for near-term financial obligations, including credit card debt and mortgage payments. But more than one in five, or 22%, withdrew money early from their retirement because of a recent job loss.

Treating your 401k account as an ATM is not a good idea irrespective of your financial situation, unless you are bankrupt or face real hardship. If you desperately need the money, the better option is to take the loan from your 401k or IRA. Marketwatch folks wrote a detailed article that gives information about various options to handle your individual situation.