Just five years later, this argument makes much less sense: “Sustained monitoring” is now a part of our digital lives. And that’s why what happened on May 23, 2017, is so important.
On that day, Google announced that it would begin to tie billions of credit card transactions to the online behavior of its users, which it already tracks with data from Google-owned applications like YouTube, Gmail, Google Maps and more. Doing so allows it to show evidence to advertisers that its online ads lead users to make purchases in brick-and-mortar stores. Google’s new program is now the subject of a Federal Trade Commission complaint filed by the Electronic Privacy Information Center in late July.
Google may be the first to formally make this link, but it is hardly alone. Among technology companies, the rush to create comprehensive offline profiles of online users is on, driven by the need to monetize online services offered free.
In practice, this means that we can no longer expect a meaningful difference between observability and identifiability — if we can be observed, we can be identified. In one recent study, for example, a group of researchers showed that aggregate cellular location data — the records generated by our cellphones as they anonymously interact with nearby cell towers — can identify individuals with 73 percent to 91 percent accuracy.
