Indeed, because of a dearth of laws protecting our privacy — and almost no high-profile political discussion about the stakes at hand — Americans are sleepwalking into a future nearly as frightening as the one the Chinese are constructing. I choose the word “sleepwalking” deliberately, because when it comes to digital privacy, a lot of us prefer the comfortable bliss of ignorance. As a result, much of the surveillance engine operates underground — just beyond where many of us dare to look.

In recent months my colleagues at The Times and other media outlets have published a series of shattering investigations into modern digital surveillance. Among other revelations: Advertising companies and data brokers are keeping insanely close tabs on smartphones’ location data, tracking users so precisely that their databases could arguably compromise national security or political liberty. There are few meaningful checks on scanning for people using facial recognition, genetic profiles or other biometric data. Tracking technologies have become cheap and widely available — for less than $100, my colleagues were able to identify people walking by surveillance cameras in Bryant Park in Manhattan.

This past weekend, The Times’s Kashmir Hill reported on a company called Clearview AI that has created a tool that “could end your ability to walk down the street anonymously.” By scraping pictures from Facebook, YouTube and other websites to create a huge database of faces, the company lets cops identify people just by snapping a photo. It’s Shazam for faces, not very different from the kind of facial recognition tools we worry the authorities may be using in China — and even though hundreds of police departments may have access to it, almost no one outside the company understands how it works.

The Clearview AI story suggests another reason to worry that our march into surveillance has become inexorable: Each new privacy-invading technology builds on a previous one, allowing for scary outcomes from new integrations and collections of data that few users might have anticipated.

I was recently confronted by this sort of cascade with my own smartphone tracking data. Late last year, with the help of Stuart Thompson, an Opinion editor, I set up my phone to monitor how certain apps were tracking me. I focused on apps that required me to grant them access to my physical location — among them apps to find cheap gas, coupons and nearby retail discounts, and to otherwise help me navigate and find deals as I wandered about the world.

The upshot: As the location-tracking apps followed me, I was able to capture the pings they sent to online servers — essentially recording their spying. I sent the data to Stuart and his team, who interpreted and mapped the pings the apps had collected about me. Their picture shocked me; the apps had followed me far more closely, capturing much more data and far more often, than I had imagined when I’d said yes to their tracking.