Last year it seemed Mark Zuckerberg was looking for a way into politics. Now he could be looking for a way out.

The Facebook founder has been called to testify before Congress starting Tuesday. He’ll face tough questions about how a Trump-affiliated data-analytics firm got hold of personal information belonging to nearly 90 million of the social-media site’s users. On Wednesday he told reporters he’d made a “huge mistake” in not prioritizing the protection of user data.

That’s a bit like a casino apologizing for letting you lose so much money at the craps table. Facebook exists to sell access to user data.

“No company better exemplifies the Internet age dictum that if the product is free, you are the product,” wrote the British journalist John Lanchester last year. Zuckerberg realized early on that advertisers, marketers, political opposition researchers, academics and data nerds of all stripes would kill to get their hands on your likes and dislikes. If he was going to make any money off his dorm-room doodle he was going to have to sell you out.

More than a decade into the social-media experiment, we can no longer claim ignorance about Facebook’s business model. Still we go right on shoveling wheelbarrows of our most personal information into its insatiable maw. Facebook knows our politics, our tastes in food, our religious affiliations and our sexual orientations. It knows who our friends and enemies are. It has developed taxonomies of our family relationships and work histories. It tracks us everywhere we go on the Internet. It can identify us by sight, using digital face-recognition technology to analyze our photos.

We give them everything; they give us — what, exactly? The “huge mistake” in this arrangement was probably ours.

Facebook isn’t the only Silicon Valley behemoth that monetizes personal information. Google, Apple and Microsoft are all inviting advertisers, researchers and government agencies to find you through their platforms. What’s revealing about the Cambridge Analytica affair is that Facebook’s critics seem more exercised about the Trump connection than they do about the data breach.

Why shouldn’t Facebook let a political firm use the data it collects? Would you be as upset to learn that they’ve the let the makers of “Sherlock Gnomes” do the same thing?

Whether this Brave New World keeps you up at night could depend on your age. Recent reports have millennials leading the charge to delete Facebook and other social media. Don’t buy it. If they’re deleting it’s because they’re bored, not because they’re repulsed by the Cambridge Analytica affair or suddenly started caring about digital privacy.

I’ve had millennials tell me they don’t worry what Facebook, Twitter, Amazon or Google know about them because they’ve got nothing to hide. And anyway, the big tech companies are ambivalent about your personal peccadilloes, millennials say. They only keep such close tabs because they want to make it easier for you to find what you’re looking for online.

Millennials believe that everyone is eventually going to know everything about them anyway

A 2015 survey by the American Press Institute found just 20 percent of millennials worried “a good deal” or “most of the time” about online privacy. The vast majority said they never worried or only worried a little about how much searchable personal information about them was available on the Internet.

Why such nonchalance among the digital natives about privacy? Millennials believe that everyone is eventually going to know everything about them anyway. They think total transparency is the price of admission to the social-media wonderland. The more you give up, the more you get in return.

“If today’s social media has taught us anything about ourselves as a species, it is that the human impulse to share overwhelms the human impulse for privacy,” wrote Wired magazine founder Kevin Kelly in his 2016 book, “The Inevitable: Understanding the 12 Technological Forces That Will Shape Our Future.”

This is undoubtedly true, but it marks a stark departure from the attitudes of previous American generational cohorts. The Greatest Generation would surely have taken a pass on the telephone if the trade-off was that Ma Bell could eavesdrop on their calls and sell what it learned to Sears and Roebuck. Baby Boomers and Gen Xers both understood that opening someone else’s mail was a felonious act.

Millennials have made peace with the idea that they won’t have any privacy. In fact, they’ve learned to love the idea that nothing is off-limits, everything is for public consumption and everyone is always on display. The millennial view of life is a kind of online competition to see who can curate the most glamorous and mysterious Instagram feed or tweet the most savagely clever political retort.

Mark Zuckerberg is in many ways the uber millennial. He appears to believe his youth, energy, intelligence and success entitle him to fly above it all. He’s managed to build a $500 billion company out of baby pictures and online surveys while giving away almost nothing about his own personality. Many will tune in just to watch the billionaire boy wonder squirm.

Entertainment value aside, the upcoming hearings could do the world a service by reminding us that our personal information is Facebook’s product. Let’s see how the man who built that system likes it when it’s his data on display.

Matthew Hennessey is associate editorial features editor at The Wall Street Journal. His book “Zero Hour for Gen X: How the Last Analog Generation Can Save America from Millennials” (Encounter) comes out August 14.