The U.S. Postal Service has confirmed that a laptop computer issued to Postmaster General John Potter and containing the zip-code information of over 280 million Americans was allegedly left in a taxicab Monday evening. 'I sincerely regret that my carelessness has made precious five- and nine-digit codes, which are vital for U.S. information delivery, potentially vulnerable to unscrupulous individuals who would do us harm,' Potter said in a televised press conference Tuesday, during which he also announced his resignation. 'I have failed the president, the Postal Service, and you, the American people, by not securely safeguarding this sensitive data, which pertains to the current locations of literally hundreds of millions of U.S. citizens. I have no choice but to step down, effective immediately.' Officials refused to elaborate on the extent of the information leak, but did not rule out the possibility that everyone in the U.S. might have to move. 