This post sounds like you lost to AI in a competition and decided to get revenge by stalking the author. I'm not even sure if you are actually concerned about its users or you're just using this information to justify the morality of your actions.

Why didn't you just send them an e-mail to warn them about the security issues?

I see in a comment that you did disclose. You should probably include that in your blog post or people will have the wrong idea about you.