I found out recently that Facebook is embedding tracking data in the form of IPTC metadata in images that you upload. This way the images can be tracked even after you download them.

Because I'm an anarchist and just want to watch the world burn a little, I made a tiny server to replace the id hash that they embed with a random one, just to see if I can't fuck with their algorithm a little bit.

You can check out the project here https://github.com/watzon/fbmdob