A reminder about privacy

Computer science, in essence, is about the processing and storage of information. But we need to also consider not just what we can do, but whether we should do it.

For example, we use passwords to protect many of our accounts and data, but the top 10 passwords are just:

  • 123456
  • 123456789
  • qwerty
  • password
  • 111111
  • 12345678
  • abc123
  • 1234567
  • password1
  • 12345

But unfortunately, even a more complex password can be quickly guessed by modern computers. We can write a program in just a few minutes, that will generate all possible PINs and check them. We can even open a dictionary file that has all English words, and iterate over each of them.

Dictionary attacks are often successful because many users and businesses use ordinary words as passwords. These ordinary words are easily found in a dictionary, such as an English dictionary.


Cookies are not just tasty but in computer language they hold small pieces of data that websites store on our computers when we visit them, useful for identifying us. This means that we don’t have to log in on every visit, but can also be used for advertising and tracking purposes.

In Chrome, we can use View > Developer > Developer Tools to see the cookies that a particular site leaves under the “Network” tab:
image of Google Chrome request with line labeled set-cookie and some values

And on other websites, where Google’s ads might be embedded, Google can track us there, too, with the same cookie.

And the request that our web browser sends to each site also includes a string called “user-agent”, which describes the version of the browser we have. I hope you’re not still using Internet Explorer.

On the internet, too, we have unique IP addresses that identify us so that we can receive responses from servers.

You can recover “deleted” photos and services like Snapchat that promise to delete photos after some time, may not actually remove the data.


In fact, a “soft delete” might set a value of “deleted” to be “true” to hide it from us, but the rest of the data is still stored.

Photos of ourselves on social media, too, can help someone else track us, what we do, and who we’re with.

Imagine the weird stuff they’d find out about you

In the Chrome’s Developer Tools again, we can run some code in a website that prompts us to share our location and then puts it on the screen:
image of Google Chrome console with function for navigator.geolocation.getCurrentPosition aned coordinates displayed in body

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