Privacy? I don't have anything to hide.
Over the last 16 months, as I've debated this issue around the world, every single time somebody has said to me, "I don't really worry about invasions of privacy because I don't have anything to hide." I always say the same thing to them. I get out a pen, I write down my email address. I say, "Here's my email address. What I want you to do when you get home is email me the passwords to all of your email accounts, not just the nice, respectable work one in your name, but all of them, because I want to be able to just troll through what it is you're doing online, read what I want to read and publish whatever I find interesting. After all, if you're not a bad person, if you're doing nothing wrong, you should have nothing to hide." Not a single person has taken me up on that offer.
-Glenn Greenwald in Why privacy matters - TED Talk
If you think privacy is unimportant for you because you have nothing to hide, you might as well say free speech is unimportant for you because you have nothing useful to say.
The right to privacy is the right to self. You "own" you. You decide when you want to share you and when you don't. It is really just that simple.
There are also things we, as a society, have decide we don't think is generally right to share. This is why we have bathroom stalls with a door that can be closed and locked versus just using toilets on street corners.
As long as there have been windows, there have been curtains. Privacy is part of human nature.
Have you ever asked a friend if they needed privacy? Their answer is probably no.
I simply don't believe your friend if he claimed that there is nothing for people to steal from his computer.
Has he ever used his computer to buy something online? If so, his computer could have stored some credit card details or personal information on him, like full name, address, etc. If you frequently buy goods from companies like Amazon, they might use that data together with data from google to guess your demographic.
Has he ever written something online on any topic? If you write about the wrong topic, that might have consequences.
Has he ever connected to the internet outside his own house? That can be used to pick up behavior patterns and people's social networks.
Is he ambivalent towards computer security? Someone might get remote access to his computer and steal his identity or at very least use his computer for shady things and leave him to blame.
In fewer words, it's not just what you store on your computer, but what you use it for. He might not have dick pictures stored on his PC, but if he doesn't take computer security and privacy seriously, someone might upload their dicks to his computer.
And the last point: Thinking it's only about individual choice is extremely egoistic and self-centered. How everyone treats privacy and computer security affects everyone else. It's kind of like vaccination; it is a social responsibility everyone has. If you don't value your own privacy, you should at least acknowledge the concept is important, that it matters for others and take the necessary steps for the greater good. For example, if information about your social network or location data leaks out to someone else, you are not the only victim.
Conclusion
When people say they have nothing to hide, never attack them. It will put them in a defensive mode and its harder to get your point across. You also make yourself look like a lunatic. Seeing someones password is not an realistic scenario, and the reply would be simply be "I trust the gouvernment/facebook/corperation more then you". After that you are simply digging yourself into a hole after that point.
You have to create a patos to them using an example. Ask them if they leave their door locked, or have a curtains. Try get them to explain WHY, as in "does it make your uncomfortable that people look inside your own home?". Convey your point across using this feeling. I also enjoy adding an example as simple as singing in the shower. I do it home, alone in the shower. It's not dangerous for anyone, but i enjoy doing it in the privacy of my own home. I would never dare do it to anyone else, except for myself. That is privacy.
Another example i'd love to try and do to a live audience, is get a police officer to attend. Ask if anyone who got nothing to hide would be so kind to let the police officer read their SMS or Facebook messages out loud in a private room. My assumption about this is that it would make anyone highly uncomfortable, and this is even a realistic scenario.
This article is sourced from articles across the web