I worked in a small company in past. I had a very bad experience with them, since before I even joined. They delayed my hiring for several months (so I was basically unemployed for several months). Working conditions were also very poor compare to other companies here. In the end, I had to quit within 6 months. It was a very bad experience for me.
I wanted to write a poor review for them since before I even joined because of so bad experience. And I think it will give me great pleasure to write a negative review about them. I know they will realize it's me, but I don't care. There is also no doubt I don't ever want to apply there again in my life too.
My question is: What are the risks in writing a bad review of ex-employer on Glassdoor.
It's a small company so I am assuming, they will easily know it's me. It won't be anonymous at all for sure.
Update: I personally disagree with the primary opinion-based flag. I am not asking if I should do it or not. I am asking what are the disadvantages in doing it. The answers below offered facts about how it can go wrong on me.