I have a fun story about open FTP servers. When we were undergrad students, a friend and I wondered exactly that same question about FTP servers. So we wrote a

I have a fun story about open FTP servers. When we were undergrad students, a friend and I wondered exactly that same question about FTP servers. So we wrote a script that tested random IPv4 for FTP servers using nmap and then attempted to connect. To our surprise we found quite a few. Most of them were small or not writable, but at least one of them was writable, and it had hundreds of GB of free space. So we connected to it, and then saw that it had huge data files containing what seemed like random junk. Then, we tried to ssh to the box, but no ssh server was listening. So we tried to telnet in. That worked but we were prompted: Enter password: Ah, too bad, we will never guess what the password is… Mh, let's try "123456" just in case… But then, instead of logging us in or telling us that we entered the wrong password, it simply said: Re-enter password: Mh? So we re-entered "123456". The password has been set. Haha! The owner must never have set this up. And then we were in. It was a very strange system with a few commands with standard names but non-standard behaviors, and a very minimalistic shell. By poking around and searching the web, we understood that we were actually connected to a surveillance camera and that the big files were probably parts of video. Poking around more gave us access to other such cameras in the same network and more importantly to a web interface from which we could see the videos streaming live. We saw offices and people doing stuff like taking the garbage out (I don't know why but that is one of the more precise image I can recall ^^). The only distincive thing I remember was a big sign saying "Miami Fitness Club". After that we never did anything about it as we had other things to do, but I kind of cherish this story as a nice souvenir of my first year at the ENS.