A system and method are described to track and warn a person suspected of texting while driving a moving vehicle. The position and speed of a user's cell phone are compared with those of other cell phone users in the vicinity. If the position and speed of a phone track that of one or more neighboring phones, it is assumed that a user may under certain conditions be texting while driving. For circumstances where persons suspected to be in the same vehicle utilize different service providers, parameters such as for instance cell phone position, velocity, and direction of travel are time stamped and passed between service providers or alternately made available to other service providers via a central database. Cell phone users who are determined likely to be texting while driving based on the disclosed methods may be warned without disabling their texting capability.