This Google shows all the companies listed within Google’s index with the “Glassdoor Alert: Employer Legal Action” flag; just kept removing the companies for the SERPs using the negative search operator until none were left. No idea why Glassdoor doesn’t just have a list of all the companies doing this.

https://www.google.com/search?q=Glassdoor+Alert:+Employer+Le...

Manually curated list from parent process:

-Steidle

-legatum

-Medspira

-Media Consulta

-Keller, Fishback & Jackson

-ABG Accessories

-Echelon Environmental

-Admiral Markets

-canidae

-Discovery Clinical Trials

-kraken

-zuru

-bw legal

-kurland

-SynapseFI

"did not match any documents"

Because they removed all the companies, remove the "-company name" paramters from the search.

This page gives a little context about when they post such warnings:

https://help.glassdoor.com/s/article/Glassdoor-Alerts-Badge-...

Based on the wording on this page you have to be pretty flagrant to get a warning sign attached to your company.