This is what they do with voice-based services where users dial a number and state their location. In both cases, subscribers retain control of when to use the service. To avoid being located, a buddy can turn positioning off, or just disable selected subscribers temporarily or permanently. An alternative would be to send an explicit request to the buddy each time the subscriber asks for his or her position. However, this would soon prove impractical and, should the buddy deny access to the position, the subscriber could check whether the mobile phone is on and speculate about reasons for denial.
Individuals can monitor how their relatives and friends move.
In particular, employees provided with a company-owned cellular phone may have a list of colleagues and bosses who can access their location already embedded in the SIM card. The use of electronic means to monitor employees and their behavior is illegal or clashes with union agreements in several European countries. Enterprises can control the mobility of their customers. Enterprises need to involve their legal counsel to analyze the implications and how the regulatory framework might evolve. Liabilities may also arise from erroneous or inadvertent transmission or storage of location information.