One thing to understand is services which deploy personal knowledge questions for password reset do NOT take security as their primary aim. The primary aim wil

One thing to understand is services which deploy personal knowledge questions for password reset do NOT take security as their primary aim. The primary aim will be a cost-benefit optimum between user security and cost of customer service. This cost-benefit analysis is strictly from the point of view of the provider. If their costs for a customer security breach are low, they will be willing to trade lots of insecurity for a little bit of reduced customer support.