A proposal to register all customers of mobile phone services was considered previously by my Department. It was concluded that such a proposal would be unlikely to solve the illegal and inappropriate use of mobile phones by persons determined to use the technology for illegal activity. There is also a risk that such measures could lead to the emergence in a black market for fraudulently registered or stolen SIM cards. Furthermore, there are significant data protection issues associated with such a proposal.
For those reasons I am not currently considering any plans to make it mandatory for persons to need to register for mobile phone services.