Firebase is pretty simple to use, and possibly because of this, I've seen quite a few terrible implementations. I think it attracts people who only know app development, where security, scalability, authentication, etc, are not really a concern because you have exactly one user on one device.<p>It's easy to accidentally make a bunch of information world-readable, and if a malicious user gets hold of the right details they can simply read all your content out, or even start writing bad content in, racking up a bill in the process.<p>Whether this is what happened here or not I have no idea. And I don't think this is even really a problem with Firebase, just an indicator of the sort of developer who ends up using Firebase and their background.