I recently found out about this. Facebook can figure out people you might know by analyzing the pattern of dust and scratches on a camera lenses. Facebook filed a patent for their “people you might know” feature, the thing that recommends someone that you might want to become friends with on the social network site.

And the way that it works is this: Imagine we’re at an event and I’m taking pictures. I take a photo of you that you really like. We don’t know each other but I show it to you, I send it to you and you post it on your Facebook page. I do the same thing with someone else.

So none of us are in the pictures, none of us know each other, I’ve just taken a picture of you and someone else, and you both posted them on your Facebook pages.

Facebook can then analyze the scratches and dusts on your camera lenses that were on my camera and find the invisible artifacts that those scratches left in the photo to determine that you both had your pictures taken by me at the same time and then recommend that you become friends.

When reporters found this patent, Facebook denied that they were using it in their system but there’s no way to know if they’ve started using it since or if they’ve put it in something like Instagram and WhatsApp.

This is how much trouble we have to protect our privacy.

After WhatsApp updated its privacy terms and millions of users got angry, people started to move from it to Signal and Telegram. It even caused some problems for Telegram and Signal servers as they didn’t expect that much users.

Signal is known for its encryption and privacy and I think they are doing a very good job but I don’t trust them. The thing against Signal is that it’s not really free software. Signal has a code/repository that is published with a free (as in freedom) license but the app itself is not libre.

Signal’s app is not on F-Droid. The only way to get Signal’s app is to download it using Google Play Store. When many people complained, they published an APK which is really really hard to find and is still using Google Play Service, if it’s available on your phone.

Signal doesn’t let you connect to Signal using the app you created yourself. Even if you compile their exact source code, it will only be active at most for 90 days.

But what I use instead of Signal and Telegram? I use Matrix and XMPP. They are decentralized messengers and truly free (as in freedom). With Matrix and XMPP, I have true liberty over my computing and messaging. I can run my own server if I don’t trust others and I can make sure encryption works the way I want.

I can compile/build my own app and know for sure that the app works as it is expected. Unlike WhatsApp, Telegram, and Signal which have centralized servers, Matrix and XMPP are decentralized and there’s no main server. I know for sure what’s happening on the server (as I can run my own) and I’m sure the app communicates with server exactly how it says so or I want it.

Many intelligence agencies or tech companies try to fool people by telling them that their backdoors are only for good people. I think there’s no need to say that’s a lie.

There’s no meaning in encryption or security when there’s a backdoor. There is no such thing as a backdoor that only lets the good guys in. If there’s a “master key” that unlocks millions of accounts, every cracker on the planet will be after it.

A compromised encryption backdoor could give cyber criminals access to your bank account, your personal messages and other sensitive information.

Don’t think crackers can steal the master key? Think again. Both the CIA and the NSA were breached in 2017 by mysterious organizations that stole and published the spy agencies’ cracking tools. The same year, cyber criminals stole an NSA exploit and used it in a massive, worldwide ransomware attack. The fact is, if the government or anyone else controls a master key, eventually it will get out.

Crackers aren’t the only threat: Governments may also use encryption backdoors for harm. The U.S. government has already revealed its willingness to spy on citizens without a warrant. If liberal democracies cannot be trusted, what about China, Russia, Saudi Arabia, or countless other authoritarian states? Encryption backdoors could be used by repressive regimes to help them persecute journalists, dissidents, religious minorities, the LGBT community, and anyone else they please.

I’m a fan of decentralized networks. I use Mastodon instead of Twitter, I use Pixelfed instead of Instagram, and I use IRC and XMPP instead of Whatsapp. I’m very well satisfied with my experience. I don’t feel lack of any social network or messaging system.

I respect myself, therefore I don’t use proprietary apps and networks. If someone needs to contact me or have a digital social relationship with me, then that person can start a respectful relationship by using free software and privacy-minded networks.

However, I should mention that not all of Fediverse or decentralized services/products are good. For example, some programs/networks don’t have a good user experience.