Sidestepping the need to obtain a search warrant, the US Department of Homeland Security (DHS) has been accessing smartphone location data by buying it from private marketing that typically embed tracker in apps. This data, which maps the movement of millions of cellphones in America, was collected from ordinary cellphone apps, to which users gave access to their location. In this particular instance, it was used by the DHS to search for undocumented immigrants according to the Wall Street…