US telephone companies sell location data in real time

According to different media, four of the largest telephone companies in the United States are selling the location data of their clients, through an intermediary, to private and governmental organizations, sheltering themselves in a legal loophole in the privacy law.
The intermediary company, LocationSmart, has access to 95 percent of the country's coverage and, according to its website, they use the same technology used in emergency calls to geolocate users, that is, gps and triangulation of the telephone antennas.
LocationSmart also indicated that in order for their clients to have access to the geolocation data, users had to give their consent explicitly, although in some specific cases the consent was implicit.