I do have such a list, available on nice request. But it remains closely by my side, as it would definitely go against the guidelines of this forum to openly post it, as doing so would, as Maddyks correctly posted, incite a war. Of my blacklist, I am very sure of where I stand, and I do record down the reasons/wrongdoings of those on my list.
After that, the thread title is "Blacklist available?". I have a couple more blacklists too, you know... one for F&B outlets that I'll never patronise, one for bad webhosting, one for rotten photo labs... it goes on. But most of them are not photography related.
On a serious note, I think it will be a good thing, albeit a private one, amongst us working/professional photographers, to share in such bad eggs. But do so in private. It won't do to publish it and turn it into a flame-war. By token of this, let those who are keen to know, to contact me directly. I'm very open to sharing my blacklist, over a cuppa, face-to-face. Good too, for fellow photographers, to know who to avoid.
So, Vince123123, would you prefer to clarify if what you mean to allude to by this segment of your post?