“But, when I talk to people in general, most seem to not worry because they “have nothing to hide”, and most are only worried about their passwords, banking apps and not much else.”

Sounds like they have passwords and banking apps to hide, You should demand their bank account and credit card details to verify that they have made no illicit actions.

If they point out that they have no reason to trust you with that information, that’s when you point out that police, government, or corporate groups are made out of people just like yourself. They might have some codes of conduct, or a vetting process, but it just takes one person malicious or careless enough for you to be severely impacted.

Cite historical examples of seemingly innocuous and public information falling into the wrong hands.

e.g. The Nazis used demographic records (marriages, births, christenings, etc.) in conquered lands to ID Jews and other “undesirables”.

Saying “I don’t need privacy because I’ve got nothing to hide” is like saying “I don’t need free speech because I’ve got nothing to say”.

Ask them for their social security number, mother’s maiden name, favorite pet, favorite teacher, high school mascot. It should start to dawn on them

Edward Snowden remarked:

Arguing that you don’t care about the right to privacy because you have nothing to hide is no different than saying you don’t care about free speech because you have nothing to say.

There is a wikipedia article regarding this argument

One thing I often see is people not understanding the difference between secrecy and privacy. They ask why it matters if you’re not doing anything wrong. A UK government minister actually said “if you have nothing to hide, you have nothing to fear”, and then backpedaled when someone pointed out they were quoting Joseph Goebbels. The analogy I’ve seen is simple: I’m sure you don’t do anything illegal in the shower, but I’m also pretty sure most people would be uncomfortable with a law that required you to have a police officer standing in you bathroom with a video camera to record you showering, just in case.

The other thing is the assumption that any information about you that the government actually has about you will only be used against you if you commit a crime, in which case you’ll deserve it - if you’re not a bad person then it’s fine. This is a double fallacy.

First, we’ve seen that information can be used to do all sorts of things regardless of wrongdoing - if someone knows enough about you, they can use it to manipulate you. I don’t mean blackmail or whatever, although that’s an option. I mean that with a clear enough picture of your preferences and biases and habits, someone can tailor their actions and information to your psychology and make you think whatever they want you to agree with.

Second, it assumes that you won’t ever commit a crime because crimes are bad things and you’re not a bad person. This overlooks the possibility of you being mistakenly accused while innocent, but more importantly it overlooks the possibility that the government will change into something that holds different moral values to yours. Even in the modern world we’ve seen places outlaw abortions, or criminalise homosexuality, or pass laws on what religions you’re allowed to follow. If that happens in your country and you find yourself on the wrong side of whatever arbitrary line they’ve now drawn, you may regret giving them so much information about you - information that lets them identify you, prove that you broke their new rules, and ruin your life in so many ways.

The default principal of any exchange with governments, businesses, or any entity taking your information should be to give as much information as is required for them to perform the operation you’re requesting of them, and no more - and wherever possible to only engage with those entities that you trust to have that information; a trust that they earn by a verified and unbroken track record of ethical and trustworthy behaviour.

I may have nothing to hide, but that doesn’t mean I want it on public display either.

Do you have curtains in your house? Can I look at your income tax records and all purchases made on your visa and bank card?

I feel like most replies here are missing the point.

The entire premise of the statement is that privacy is about defending your dirty secrets. When people say “nothing to hide” they’re really saying “I’m not going to post about anything I want to hide”, but that still misses the point.

For me it’s the subtle principles of advertising. I don’t want to be advertised to, at all. I certainly don’t want some blog to know what adverts I’m likely to engage with, because that is simply none of their business.

That’s it. If that doesn’t bother some people, that’s entirely fine. I’m a bit weird, and the whole idea of being tracked to figure out what things I might want to buy makes me very grumpy.

Just ask them a bunch of indiscreet questions. Do you watch porn? What category of porn turns you on the most? Do you think it’s appropriate to have sex in a room on the ground floor without curtains? What? You own curtains? What is your salary? What’s the amount of money in your savings account? Why do you have so many loud disagreements with your partner? Don’t you like visiting your in-laws? What’s inside the drawer at the bottom, next to your bed? Have you had any embarassing and cringy moments in the last few years you’d like to share?

Of course this is only the beginning. It’s not like the corporations collect data and then don’t do anything with it. You’d also have to be okay with them deducing information about you. Try to use that information to manipulate you into giving them attention, buying the stuff they want you to buy. That system is in place to nudge you into thinking what the algorithm wants you to think. App developers are actively trying to make the apps more addicting so you spend more time with them… People just get exploited with the help of all of that data.

If people really are that tame and have no secret fantasies, no sensitive data, no shame, no personal shortcomings they’d like to forget… And they don’t care about the annual security breaches of big platforms people use willingly, but that information then gets used by people who use it to send you spam or impersonate you and trick your grandma to send her retirement to some scammer… And they like to be shoved around by big corporations like cattle, used to fuel the capitalist system… …I myself tend to leave them alone. There is nothing that can be done at this point. Those people are lost, and they don’t want freedom for themselves.