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Metadata — What is it and why is it dangerous?

Daniel Nelson
3 min readMar 26, 2021

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Every day millions of people are sharing their personal information when they capture, share, download, and upload digital photographs. I’m not just talking about sharing what they look like, but something far more dangerous. I’m talking about metadata.

What is metadata?

By definition, metadata is data that describes data. Many files contain extra or even hidden data other than the visual data you see at first glance. E-books, photographs, movies, music and even documents can contain data underneath the surface. Metadata is any data that doesn’t directly expose any sensitive information but can be used to expose information about something or us.

Metadata can be added by a user, software, or digital camera. The information embedded in the image can contain:

• Copyright Information

• Text comments/descriptions

• GPS location

• Original image thumbnail

• Serial numbers

• Date and time

For example, a library uses metadata to sort the books by title, author and publishing information, and the library needs only two of these pieces of information to find the correct book. This can be compared to our digital lives, where even though your messages are encrypted, there may be metadata collected, such as names of people talking and the times they interacted and for how long. All things that can be used to discover what is being said.

Why is it dangerous?

In one example, the metadata shows that you used your phone to make a call to a health clinic, then your doctor, and then your health insurance company, all in the same hour, but they don’t know what was discussed. Therefore, just because the contents of the call or message is confidential, doesn’t mean there isn’t data being collected that can give more than enough information to figure things out.

Now, even if you don’t do anything wrong, it can only take one person to can ruin it for everybody. The FBI in the United States wanted to obtain Edward Snowden’s emails from Lavabit, an open-source encrypted webmail service (not sure what open-source software is, read here). The FBI forced Lavabit to hand over the SSL key (used to secure your login details) and subsequently gained access to over 400,000 users on Lavabit and their ‘private’ emails!

As mentioned in the first paragraph, whenever you take a photograph on your smartphone, the picture contains exchangeable image file or (EXIF) data. EXIF data is photo metadata that contains timestamps and even uses the GPS location of your phone to provide the exact location when you snapped the photo! (This is why the camera app on your phone asks to use your location)

If you wish to view the metadata of your files, you can use this website.

Conclusion

Metadata is data about data, and more precisely, metadata describes data containing specific information like date, authors, textual description and more.

Metadata does serve a variety of purposes, with resource organisation and discovery one of the most common. For archiving and preservation purposes, it takes metadata elements that track the object’s lineage, and describe its physical characteristics and behaviour so it can be replicated on technologies in the future.

However, metadata in the wrong hands can seriously jeopardise your online privacy. In extreme cases, hackers could manipulate metadata to steal your identity or sell your private information.

I hope this article has made you think twice about and always remember you have the power to decide what you share with the world online.

-PocketPound

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Daniel Nelson

Hi, I’m Daniel. I am the founder of PocketPound — a website designed to help you organise your finances, as well as, stay safe online.