Data, Metadata and privacy is a really big and broad topic. I tried to show some aspects which should be easy to understand and have easy solutions. Still, I will probably touch this topic once again in a very distant future. Nevertheless there are more interesting and 'practical' topics on the way. As I have mentioned - it is a warmup :)
Btw, it is not only about stalkers. I hope I gave some hints to those who would like to e.g. know how to process and categorize images, learn from them or... well, hide something inside.