The FBI has confirmed to the Senate that it is purchasing location data that can track US citizens, working around Fourth Amendment protections by buying information from commercial data brokers rather than obtaining it directly from mobile networks. This practice sidesteps the legal precedent set in Carpenter v. United States, which required warrants for law enforcement to obtain location data from telecommunications companies.
The data originates from the online advertising ecosystem through a process called Real Time Bidding (RTB), where user attention is auctioned in milliseconds after a webpage loads. When phones connect to the internet, they broadcast information including IP addresses, device types, and GPS coordinates through "Bidstream" data that advertisers use to target users.
Data brokers aggregate this location and browsing information with additional personal details that users provide when signing up for platforms, such as names, email addresses, and income levels. Even banks are exploring licensing anonymized customer data to these brokers as a new revenue stream, creating comprehensive profiles that can be sold to various buyers including law enforcement.
This commercial data marketplace allows federal agencies to access citizen location information without judicial oversight, effectively circumventing constitutional protections designed to prevent warrantless surveillance. The practice raises significant privacy concerns as individuals have extremely limited ability to opt out of this data collection and sale ecosystem.