Location-blocking and identity-blocking services that can be commercially offered by a service provider, e.g., a cellular service provider or a web advertiser. In the identity-blocking service, the service provider may disclose the current physical location of a mobile subscriber (i.e., a cellular phone operator) to a third party (e.g., a web advertiser) subscribing to the identity-blocking service. However, the service provider may not send any identity information for the mobile subscriber to the third party. On the other hand, in the location-blocking service, the service provider may disclose the mobile subscriber's identity information to the third party, but not the current physical location of the mobile subscriber. Blocking of the mobile subscriber's identity or location information may be desirable for privacy reasons, to comply with a government regulation, or to implement a telecommunication service option selected by the mobile subscriber.