Metadata matters! Your metadata is just as important as the actual data, even a tiny sample of your metadata can provide exorbitant amount of intimate data about your personal life.
People usually don’t care a whole lot about metadata in general, and those who collect or demand access to metadata like the government and corporations argue that it’s not a “big deal”.
Unfortunately, that’s not the case, NSA General Counsel Stewart Baker has said,
Metadata absolutely tells you everything about somebody’s life. If you have enough metadata, you don’t really need content.Stewart Baker
In 2014, former NSA and CIA director Michael Hayden remarked:
We kill people based on metadata.Michael Hayden
Alright, now that you are aware of the importance of metadata, and why you should protect it, let’s dive deep to find the ways to do just that.
How Revealing is Metadata?
Let’s have a look at how revealing metadata can actually be to the government, corporations, and other adversaries, as explained by EFF:
- They know you rang a phone sex line at 2:24 am and spoke for 18 minutes. But they don’t know what you talked about.
- They know you called the suicide prevention hotline from the Golden Gate Bridge. But the topic of the call remains a secret.
- They know you got an email from an HIV testing service, then called your doctor, then visited an HIV support group website in the same hour. But they don’t know what was in the email or what you talked about on the phone.
- They know you received an email from a digital rights activist group with the subject line “Let’s Tell Congress: Stop SESTA/FOSTA” and then called your elected representative immediately after. But the content of those communications remains safe from government intrusion.
- They know you called a gynecologist, spoke for a half hour, and then called the local abortion clinic’s number later that day.
Alright, now that you are aware of how revealing metadata can be, and what can be the repercussions, lets have a look at what you can do to protect yourself.
What is Metadata, & Why Metadata?
Metadata is basically data about the actual data, it is everything except the actual content or data. Kinda like the envelope that contains information like sender, receiver, and destination of a message. Here are a few examples of what metadata looks like:
- the subject line of your emails
- the sender’s identity
- the receiver’s identity
- the length of conversation
- the IP address
- your location when communicating
Metadata is usually important to communicate, like in the example of mail, the envelope should have details like sender, receiver in order for the mail to reach the intended person, just like that digital communications also need the source and destination.
Email service providers need the receiver and senders email address, the web browser need IP address to connect to the website you want. You need to send some amount of metadata if you want to communicate.
How to Deal with Metadata?
Dealing with metadata can be tricky as it is important for the communications on the internet. There’s basically two things you can do to prevent misuse of your metadata:
- Minimize the metadata
- Encrypt the metadata
Consider switching to apps and services that don’t require that much metadata and even if they do, they encrypt it while in transit so that no one can eavesdrop.
There are many apps and services — encrypted messaging app like Signal, Briar, Element, private search engines like DuckDuckGo, searX, Qwant do not track you, and collect minimum amount of data. Check out this list of privacy tools to learn more.
Consider using only those services and apps with whom you can trust your data with, check out the metadata policies of companies that you deal with.
Here are a few other tips on protecting your metadata:
- Turn off location tracking on your devices
- Turn off location access to your camera
- Remove metadata before sharing files, photos, etc
Metadata Removal Tools
You should remove metadata from any files that you are sharing, one way to do that is to use these metadata removal tools:
mat2 or Metadata Anonymisation Toolkit v2 is free and open source software that lets you remove the metadata of image, audio, video, and other file types, written in python3, at its core.
It is available as both a command line tool and a graphical user interface via an extension for Dolphin, the default file manager of GNOME. MAT2 does not clean files in-place, but once “dirty” files (with metadata) are cleaned, a cleaned version of files is created in the same directory with the .cleaned extension. ex: file.png → file.cleaned.png
It comes preinstalled with Tails OS, and is available for Windows, macOS, and Linux.
ExifCleaner is a free and open source app with simple drag and drop GUI that uses ExifTool to remove exif metadata from images, videos, and PDF documents. It supports multi-core batch processing so you can process tens, hundreds, or even thousands of files at once.
It has the beautiful dark mode, and unlike mat2, it removes the metadata from the original file, hence does not require creation of a new file. ExifCleaner is available for Windows, macOS, and Linux.
ExifTool is another free and open source metadata reader and writer with a command-line interface that supports a whole host of image, video, and document file extensions.
It is cross-platform, and feature-rich with lots of customizations. ExifTool is also available as stand-alone Windows executable and a macOS package.
These metadata removal tools only removes metadata from your files, it does not anonymize the content, nor can it handle watermarking, steganography, or any too custom metadata field/system.
If you really want to be anonymous, use file formats that do not contain any metadata, or better: use plain-text.
- Metadata Explained — An awesome video by Privacy International explaining what is metadata, why is it important, what does metadata reveal?
- Metadata: Piecing Together a Privacy Solution — An awesome paper by ACLU examining how outdated laws and new technologies combine to put personal privacy at risk — and highlights efforts to change that.
Metadata Removal Tools
Removing your personal metadata using the tools mentioned above combined with efforts to minimize the collection of metadata and using trusted privacy respecting tools that encrypt the metadata is the way to go if you want to protect your privacy.
That’s all folks!
I will be updating this page frequently with more metadata removal tools and information. You should check out all the privacy respecting tools that I recommend bettering protect your privacy.