She’d carried the mask around all morning. Like keeping it close would tell her whether to go.

She’d carried the mask around all morning. Like keeping it close would tell her whether to go. But she still hadn’t decided, and the protest was an hour away. Time to choose.

A heavy rapping on her front door startled her.

At first she almost didn’t understand. No one ever just came over unannounced. Not on a random Saturday morning. Then again today wasn’t exactly random, was it? Not with the protest coming. The C.P.P., Citizens Privacy Project. Drop the drones! Pop the balloons! Hey hey, ho ho, the cameras have got to go!

They needed better slogans.

“Hello?”

“It’s Dad.”

She pulled open the door. Yep, her father, in a blue wool jacket that looked new and his crinkled Cubs cap. The look in his eyes was almost furtive. Not a word she associated with him.

“Quelle surprise.” He and her mom lived in Naperville, 30 miles out. They came in once a while for the Art Institute, at Wrigley. Mostly they didn’t.

Of course, Chicago had more crime when she was little. Almost 800 murders one year. Not anymore. Not since the cameras, especially not since the drones. Officially known as Chicago Police Unmanned Aerial Vehicles. The police had always used a few, but their use had exploded since the Independence Day attacks — truck bombs three years before that had killed 1,200 people nationwide. An awful, awful day. The attacks had never been solved, and they’d bred crazy conspiracy theories.

Now the drones were everywhere. And they’d started carrying sticky nets, which they could use on anyone committing — or supposedly committing — a crime. She’d seen a takedown once. Unnerving. A guy was screaming at a cop, and then this big black plastic tube with fins, a rocket, really, came roaring down. About five feet from the guy, it blew open into a net that dropped on him. Thick mesh. He thrashed, but the harder he fought, the tighter the net became.

The creepiest part was that she hadn’t even seen the drone up there. Now she watched for them, but even during the day they were blurs. At night they were practically invisible.

And some drones now carried what the police called nonlethal audio technology — targeted noise cones powerful enough to put anyone on his knees. The police said the drones couldn’t use the sonic weapons without human approval. Though they’d said the same about the nets too, and then last year had admitted the drones could fire those autonomously.

“Quelle what?” Her dad hugged her as he walked inside. He’d never been a hugger. He was a coder. She knew he loved her, but he’d always been a little distant, in his own head.

He let her go, looked at the toast on her plate. “Soy butter?”

“It’s delicious.” It wasn’t.

“You’re gonna starve.”

“You’re gonna have a heart attack.” She wasn’t totally joking. He’d fattened up lately. He was working hard. Making lots of money too. He and Mom had bought a place on the water in Sarasota. Not a condo, a house.

“I’ll die happy. Everybody your age eats like they’re in a refugee camp.”

Let’s move on. “Mom here? In the car?”

He ignored her, picked up her phone. Last year’s iPhone. Bendable, waterproof, 7G. The camera could read a license plate on a car moving 60 miles an hour. He raised a finger, quiet. Pulled a shiny metallic sleeve from his coat, slipped the phone inside.

“What’s up?” Showing up unannounced, acting weird with the phone.

He nodded at her mask. Darth Vader. Cheap black plastic. “For the protest?”

“Yeah. So?”

“Don’t go.”

“This is ridiculous.” She was 23 years old, a college graduate. She didn’t need her dad to tell her what to do. “You know the thing with the masks is stupid.”

Lately people had started wearing masks in public. She still remembered the first time she’d seen someone on the L with a white hockey mask, like Jason in “Friday the 13th.” Creepy. This winter they’d taken off. Like the cold gave people an excuse to hide their faces behind scarves, and by spring they’d decided they liked beating the cameras.

Folks mostly stuck to a few masks, which made sense, since anonymity was the point. Jason, Vader, Guy Fawkes. Not just Chicago, either. She’d seen them in Seattle last month.

The masks were legal, for now, but the police hated them. Cops tried to catch the people in them jaywalking or littering, an excuse to write a ticket, make the wearer show his face. Which just made the folks wearing them more tense. She’d seen three cops take down a guy in a Trump mask two weeks ago, pull it off while he screamed. Now the Illinois legislature was debating a bill banning anyone from wearing a mask in public, except on Halloween. Other states were doing the same. Congress, too.

The consensus seemed to be that the laws were constitutional, that at least they would allow a police officer tell anyone, remove your mask or be arrested. And the Supreme Court had found that an order given by a police officer through a drone was legally binding. So the drones would be watching, and the masks would have to go.

People were already talking about burqas.

But the mask ban had riled people more than the other surveillance stuff. She wasn’t super-political, but she understood. The streetlight cams, the drones, the big aerials over the Reagan when she was Zipping out to Naperville, they were just … there … somehow. Yeah, they watched, but they didn’t do anything. Not to her, anyway. Not most of the time.

The mask thing felt different. The government was taking something away. A choice. A right. She’d never even worn a mask, but what if she wanted to? What if she wanted to leave work early, spend an afternoon drinking, and she didn’t want her imperfections forever saved?

Turned out she wasn’t alone. Twenty thousand people were expected in Grant Park for the protest. The plan was that everyone would wear masks, listen to speeches. Then at the end take them off and throw them up like a graduation.

Three, four, one, two, you’re watching us, now we’re watching you!

Yeah, time for new slogans.

“Dad. Why do you care?”

“Just please trust me.”

“I’m sorry. That’s not going to work.” She was proud of herself, staying cool but standing up to him.

She saw he was embarrassed. She didn’t know the last time she’d seen him embarrassed. Maybe never.

He put his big hands over his big cheeks. Exhaled, closed his eyes. Opened them again. Nodded. Choice made. He stepped closer. “You don’t really know where I work, what I do.” His voice was quiet.

“Huh?” She knew where he worked. The company was called Anodin Software. In Aurora. He’d been there 20 years, he was a managing director now. It specialized in scalable database management for machine learning networks, blah blah blah — O.K., she was fuzzy on the details, all she knew was that it couldn’t be more boring if it tried. “Scalable database — ”

“It’s just a way to say artificial intelligence.”

“I still don’t see what that has to do with today.”

“O.K., step back. What’s the biggest problem with mass surveillance?”

“That people shouldn’t have to worry about cameras all the time — ”

“No, I mean technically. The biggest problem isn’t the battery life for the drones or the camera resolution. It’s what you do with the information and how you match it to everything you are lawfully, maybe semilawfully gathering, the Instagram posts and the rest. Because everyone from the National Security Agency on down is hoovering up so much, they’re choking on it — ”

“How do you know this, Dad?”

“I told you, you don’t really know where I work.”

She wasn’t sure the last time she’d felt this young. She fell back on sarcasm. “Cool, Dad, turns out you’re like the James Bond of Naperville. Glad I’m old enough to know the truth.”

Now her father seemed almost ashamed.

She shrugged, I’m listening.

“I only see a piece of it, but I see enough. In the last two years it’s come together, we’ve built what we call IIPMs, individually identifying predictive models, for everyone — why are you smiling?”

“These acronyms.”

“This isn’t funny. Listen. Even five years ago Homeland Security had a file on every American, social media posts, real estate transactions, police reports. Jobs, plane tickets, immigration records. But now we’re scoring you, and if your score is above a certain level, the lawyers have agreed we have the excuse to track anything you do in public, in real time, from the moment you walk out your front door to the moment you come home — ”

He was right. It wasn’t funny.

“That sounds like China.”

“It is like China. Where do you think we got the idea? They’ve been in front for 15 years, but not anymore, now we’ve caught up. Might even be ahead. The next-gen cameras will have microphones that can pick up conversations from 50 feet away.”

“That can’t be constitutional — ”

“Since Independence Day the Supreme Court doesn’t like to say no.”

He was probably right. “This score the government gives you, dad. What’s it for?”

He opened his palms in defeat. “I don’t know. Truly. But I can guess. Criminal tendencies, anti-government tendencies — ”

“Anti-government? It’s not illegal to dislike the government. This is the United States.”

“No, it’s not illegal. And you can’t be arrested for it.”

There was a but coming, she saw.

“But.”

“But if someone is watching you every single time you’re outside, they’re going to catch you doing something sooner or later. Probably sooner. And now we can do that for thousands of people in Chicago alone. Nationally hundreds of thousands. Real-time, full-time, individualized surveillance. And the next generation of drones is going to be quiet enough to allow for the use of microphones, too.”

“You’re telling me this like you’re proud of it.”

He shook his head.

“From a purely technical point of view — ” her face must have shown her disgust, because he broke off. “I’m not proud of it, no.”

“Nobody knows?” She didn’t understand that part either.

“It’s not live yet. Not fully. It’s in beta. But the architecture’s there, it works.”

“It must have cost — ” She had no idea how much it must have cost.

“There’s plenty of places to hide the spend.”

“But how can it be legal?”

“Every step is legal. The information-gathering, the databases, the cameras. No one is breaking down anyone’s door — ”

“Not yet.”

“Not yet. How the lawyers see it, it’s just a priority algorithm combined with existing technology. They’re discussing how to roll it out, how to message it.”

“Message it? You mean, how to tell people that they’re going to be permanently spied on in public, if the government doesn’t like them.”

“Not random people.”

“That makes it better?”

He leaned against the counter. She could see that telling her had cost him, but she didn’t care. Another fat old man, a cog in the system.

“Look what’s happened to crime.” His voice was a mumble.

“I hope having a place in Florida is worth it.”

“Not like I’m in charge, it’s a project.”

“Get out.”

At the door he stopped. “Don’t go, O.K.?”

“There’s going to be 20,000 people.”

“And every one of them is going to get scored and moved up the list. And trust me, it won’t matter. This is coming whether you like it or not.”

“Twenty thousand people? All individually recognized?”

“That’s easy. We can do that with about 30 phones and the right software.”

When had all this happened? But apparently it had been happening all along and she hadn’t noticed.

“Maybe I shouldn’t have told you. But I love you, I wanted to warn you.”

“Maybe you shouldn’t have done it.”

“Nothing stops the future.”

Then he was gone.

This is coming whether you like it or not …

Maybe.

Probably. Her dear old dad seemed to be sure. Bears fan, proud U of I alum, builder of the surveillance state. He was full of surprises.

He’d scared her good, though.

She felt almost paralyzed as the minutes rolled by on her phone. 10:50 … 10:55 … 10:57.

And finally, at 10:58, the protest about to start, she grabbed the mask and went.

She just hoped she wasn’t too late.

Alex Berenson (@AlexBerenson), a former reporter for The Times, is the author of two nonfiction books and the John Wells series of spy novels, including, most recently, “The Deceivers.”