The answer isn't hard to figure out. Two or three pieces of information might be all it takes to mount an effective imper-sonation—the social engineer cloaking himself in someone else's identity. Get hold of an employee's name, his phone number, his employee number—and maybe, for good measure, his manager's name and phone number—and a halfway-competent social engineer is equipped with most of what he's likely to need to sound authentic to the next target he calls.