Suddenly, stuffing your nestegg under your mattress isn’t looking like such a crazy idea. Today’s debacle? Two more banks, Wachovia and Bank of America, have announced more than 100,000 more customers may be affected by data thieves.

According to an AP wire story, this brings the total number of potential victims to nearly 700,000, or so says the police in Hackensack, NJ, where the investigation has been underway for several weeks.

Meanwhile, in a separate incident, MCI announced that a laptop containing the names and Social Security numbers of 16,500 current and former MCI employees was stolen from the car of an MCI financial analyst.