“We have this underlying infection, and every once in a while it breaks out, and suddenly you have a spike of fever,” said Shoshana Zuboff, author of “The Age of Surveillance Capitalism.”

“You treat the symptom, or you don’t,” she said, “and you stay oblivious to the underlying cause.”

“The default economic model for almost every app in existence is to not only take what you give it, but to take its privileged position on your phone, in your computer, to secretly take much more than you’ve given, and to use that much more in ways that are ultimately monetizable,” Ms. Zuboff added. It’s not what these companies have done , or haven’t done, or what they might do in the future. It’s what they’re able to do, and how little say we have in it.

In a generation, large-scale facial recognition has gone from the sort of thing that might be abused by governments to a technology that widely is. It’s also both legally and practically possible for any company that gives people a way to have fun for a few minutes on their smartphones.

Discussion about the dangers of an app like FaceApp have revolved around competing possible future violations: users’ images being sold as stock photos, or used in an ad; a massive data set being sold to a company with different ambitions; a hack. But the real violation is right there in the concept, and in the name.

FaceApp, in order to do the innocent thing that it advertises, must collect data so personal that its frequent surrender and seizure could soon result in the end of anonymous free movement on Earth. This is what the app economy, often a synonym for the new economy, demands. You can make the most innocent assumptions about FaceApp and its creators and still arrive at the conclusion that it should not exist, and yet here it is, the perfect smartphone toy, with nearly a million reviews in the App Store, and a rating of 4.7/5 stars. Sound crazy? Try it again this way: How did you make that photo? Oh my God. FaceApp? I’ve got to download that. “Allow access to your photos”? O.K., “Allow.” “Enable access to the camera”? O.K., “Enable.”

If the old man in my FaceApp could talk, he might scream: “FaceApp is the singularity! FaceApp is the end of the world.” More likely, though, he wouldn’t remember FaceApp at all. If anything, he’d probably say that FaceApp was just a fun app whose makers, after a bad year or two, maybe began to wonder just how much the things they already had access to were worth, and to whom, and who, like us, didn’t really feel the need to think about just how completely we had been habituated to not think about how, whether an app failed and disappeared or became incredibly successful, the data we had given it years ago would be put to uses beyond our control or imagination.