Unfortunately, as I am not supposed to know, there could be both legal and social impacts to people I care about if I divulged such information.
There are other people in much better positions to do something about it.
Your question forced me to understand this.
Does some sort of repository for bad clients & companies exist? Could it? This isn't exactly what Yelp and BBB is for.
I'll probably let all the domains expire, except for "shit.business", that one is gold.
Have you researched what currently exists? On a cursory search nothing came up for me. Must consider legal challenges and lack of demand as possible causes.
The bad actors in the system will fight anything that would negatively impact them. Would need more aggregate support from good actors in total to make it viable.
What about some kind of info protocol so there's no single head to chop off. Maybe it piggybacks the bitcoin blockchain for verification, and uses ipfs.
Lack of community though... is hard to combat. It's also a chicken-egg problem. Build it and they will come? :)