Most people know to ignore the e-mail overture from a Nigerian prince offering riches in exchange for a bank account number. But what if the eMail appears to come from a colleague down the hall? This is “spear phishing,” a rapidly proliferating form of fraud that comes with a familiar face, reports the New York Times: messages that seem to be from co-workers, friends, or family members, customized to trick you into letting your guard down online…