The online advertising industry has built a massive surveillance machine, and the government can co-opt it to spy on us.
In the absence of strong privacy laws, surveillance-based advertising has become the norm online. Companies track our online and offline activity, then share it with ad tech companies and data brokers to help target ads. Law enforcement agencies take advantage of this advertising system to buy information about us that they would normally need a warrant for, like location data. They rely on the multi-billion-dollar data broker industry to buy location data harvested from people’s smartphones.
We’ve known for years that location data brokers are one part of federal law enforcement’s massive surveillance arsenal, including immigration enforcement agencies like CBP and Immigration and Customs Enforcement (ICE). ICE, CBP and the FBI have purchased location data from the data broker Venntell and used it to identify immigrants who were later arrested. Last year, ICE purchased a spy tool called Webloc that gathers the locations of millions of phones and makes it easy to search for phones within specific geographic areas over a period of time. Webloc also allows them to filter location data by the unique advertising IDs that Apple and Google assign to our phones.
But a document recently obtained by 404 Media is the first time CBP has acknowledged the location data it buys is partially sourced from the system powering nearly every ad you see online: real-time bidding (RTB). As CBP puts it, “RTB-sourced location data is recorded when an advertisement is served.”