I had a company do this once after they let me go. The place was a toxic personality cult around the owner/manager, and I left a Glassdoor review saying as muc

I had a company do this once after they let me go. The place was a toxic personality cult around the owner/manager, and I left a Glassdoor review saying as much. Someone at the company found it within a couple months, and then overnight several current employees had posted glowing reviews refuting mine. Certainly we wouldn't expect a personality cult to launch an Internet brigade to protect the boss' ego.