Do you have kids? Where do they go to school? What time are they off? When did you last go to the doctor? What medication do you use? Etc. Etc.

First, when you get into these arguments, always start from the viewpoint that these people do not see any worth in their data. Their convenience is worth way more than any privacy breach. That's why your goal is usually to convince them that privacy breaches can be a huge innconvenience for them, use their selfishness to advocate for their self-interest.

Quick example, what defines something that needs to be hidden changes constantly with different governments and regulatory bodies. There's no telling if your current data won't be illegal or something in the future, causing you problems. That's why it's important to have protections for your data to begin with so a future government can't just unilaterally decide to trample all over your rights.

Basically, see what they care about and try advocating from that viewpoint, not your personal viewpoint. There's a good chance you'll have a line of argument.

I find that I have more success convincing people if I put their self-interest first and foremost instead of trying to explain some grand ideology. People want something tangible, not a hazy ideal. It's only when something affects them that they may change their views.

Ask them the pin code or credit card number.

When they refuse to give it, reply "So you do have something to hide."

Ask them about their bank, all their passwords, the contact information of everyone they ever loved, ya know, in case you ever need to use that information against them or without their consent,

keep going till they are properly creeped out and as upset as they should be at anyone but them knowing that information.

If you didnt hide your preferences, likes, dislikes, etc. from ad giants like facebook they show you ads and suck out your wealth, doing psychological experiments using you - might be a good argument but people may even ignore that

I would likely go with would you change clothes with the door open? Would you take a shit in the public? How would it feel if someone took a picture of you naked? This won't likely work for those who have this kinks though lmao.

I say "yes, and you do too, that's why we have HIPPA. You think we should get rid of HIPPA?"

All the answers you got show why this conversation goes badly. No one can come up with an actual problem that data collection causes, it's all silly comparisons to giving people your credit card number or shitting in front of them.

For me, having my data collected is like having CCTV cameras in stores. Yeah, technically someone is filming everything I do. Yeah it would be bad if a private individual was filming me for nefarious reasons. But no one actually uses that data for anything bad, and it doesn't actually cause any problems.

All that happens is I get more relevant ads.