Here some members discuss about their job/company problem.Those problems which they can not discuss openly fearing action from their respective company.With mobile no.,they can be tracked down easily .So nobody will be able to express their opinions freely.Nobody will be able to take advise from others regarding their work issues like-salary,offer,harrassment,torture,opinions regarding joining particular company etc.etc.So,I strongly believe that current system is Ok in which IP address being tracked down.No mobile no./personal identity should be made compulsory.