At some point in the gig, one of their clients went to them asking them if it was possible to de-anonymize someone glassdoor review since someone still-employed worked with them. They then went to me to see if I could do it for them. They didn't clarifywhy they went to me, but I legitimately think they wanted me to "hack" glassdoor. I told them in no uncertain terms that I wouldn't do it and they backed off.
A bit later they fired the employee.. I didn't hear how they found the person, but it really spoke to the lengths that some organizations will go to burn down the lives of those who speak up.
Use this google search to find more companies that do it:
"Glassdoor Alert: Employer Legal Action" site:glassdoor.com
https://www.glassdoor.ca/Reviews/Employee-Review-Media-Consulta-RVW23674692.htm
https://www.glassdoor.ca/Reviews/Canidae-Reviews-E845482.htm
https://www.glassdoor.com/Overview/Working-at-Echelon-Environmental-EI_IE1069898.11,32.htm
https://www.glassdoor.ca/Reviews/Canidae-Reviews-E845482.htm
https://fr.glassdoor.ca/Pr%C3%A9sentation/Travailler-chez-Echelon-Environmental-EI_IE1069898.16,37.htm
https://www.glassdoor.ca/Reviews/Employee-Review-BW-Legal-RVW58014087.htm