I remember in the early 00's that people would share books and movies by using a simple command that would allow someone to zip an archive into a jpeg. For exam

I remember in the early 00's that people would share books and movies by using a simple command that would allow someone to zip an archive into a jpeg. For example, they would put a book's pdf file in an image of its cover. Someone else could then download the image, unzip it and get it's contents. I can easily imagine how someone could use this for nefarious purposes.