I was reading this post about how to respond to the "Nothing to Hide" argument against the concept of privacy. The quoted DuckDuckGo blog post lists some pretty good reasons, but I thought I'd expound on some thoughts as well.
The core of the "Nothing to Hide" argument is that if you, personally, have nothing incriminating or illegal to hide, then you don't need to worry about privacy intrusions. The argument is used mainly to justify things like state-sponsored surveillance, but might also be applicable to data collection activities by large corporations such as Facebook or Google. Wikipedia article for reference.
The first thing to understand is that even if you personally have nothing to hide, there are people who do have legitimate reasons for having to hide something, especially from the government, and that society is better off with them having that ability. The primary example of this would be anyone who helps keep the powerful in check: whistleblowers, activists, journalists, and so on. More minor examples (much lower impact) would be people planning surprise parties, people in abusive relationships, and so on.
There are of course also negative elements who have a lot to hide (criminal activities), but that is neither here nor there. There is no question that governments should be empowered to surveil the criminal elements, but that doesn't mean they should have blanket power to surveil everybody.
The quoted post from jlelse mentions the argument in the context of the contact tracing apps being developed to fight the Covid19 pandemic, and this is a prime example. If the data were handled by a centralized entity such as a government or a private company, then presumably someone with that information could use the location data to do something like identify who has been meeting with a journlist, in order to unmask his sources.
"I trust the government" or "I trust corporation X" are not good responses either. Even if these entities were purely benevolent (not likely), the mere existence of such a data store is a possible threat, since there is always the possibility of data leaking or systems being compromised.
You may ask why should you personally be concerned? Why should you bother using privacy-protecting tools or avoiding privacy-collecting platforms such as Facebook, etc. Since you personally have nothing to hide, why worry about it? I personally have nothing to hide, and in fact even write a lot about the things going on in my life in this very website, I should have nothing to fear right?
This is a very individualistic mentality. Even if you personally have nothing to hide, there are people in society who have legitimate reasons to hide something, and if we get used to or start accepting the lack of privacy or mass surveillance, then we are moving society in a direction that makes it much harder for those people to operate. The less people that are privacy-conscious, then the more that those who use privacy-protecting tools or software stand out and it becomes easier to track them.
Even though we as individual persons may not have anything to hide, privacy protections are a necessary element for society as whole to function and to keep the powerful in check. Just like public health in a pandemic, privacy is a societal concern, and we all need to do our part even if we aren't the ones most at risk. We need to push back against mass surveillance and normalize or promote the use of privacy-conscious tools and software.