"The difference with biometrics and the reason it presents a substantial threat is that if your passport is stolen, the government can reissue you a new passport number and you can move on with your life, " he tells CNN.

CNN: Fully biometric airports becoming a reality

"Never disclose sensitive details such as your social security number, passport or driver's license numbers, bank account information to prospective employers until you have established they are legitimate, " said the firm.

BBC: NEWS | Technology | Monster attack steals user data