This paper reports on a recently concluded empirical study into the development of Wireless E9-1-1 (emergency service) in Canada that initially focussed on privacy concerns raised in the context of an emerging location based service (LBS) for mobile phone users. In light of existing regulatory arrangements this paper concludes that in Canada the emerging Wireless E9-1-1 system establishes a reasonable level of protection for the privacy rights of mobile phone users who choose to contact emergency services. However, an important and surprising issue was raised in the proceedings regarding the obligation of wireless service providers offering prepaid mobile phone service to obtain verifiable subscriber records from their customers. This paper provides details regarding the issue and contributes a number of points to an emerging debate concerning the right to anonymity for customers who elect to use prepaid or other services provided over commercial networks.