The newest incarnation of the cellular phones offered by most manufacturers contain "accelerometers". These sophisticated sensors are easily co opted to determine what exactly the carrier is doing. The phone can tell if you are walking, sitting, driving, even eating.
Manufacturers of the co opting software and additional add-ons are are quick to point out the potential uses for employers.
BBC News - Mobile that allows bosses to snoop on staff developed
The obvious ramifications for privacy are tremendous. Access of the data falling into the wrong hands could bring about an entirely new level of thievery and voyeurism, especially in light of the Obama Administration's recent statement that Americans have "no reasonable expectation of privacy" as to the location history of their mobile phones.
The likelihood of acceptance, however, as a so-called "self protection" measure, or "mothering" feature is likely to allow for mass use, according to some industry leaders.