1. Look at a candidate’s LinkedIn 2. See common colleagues and reach out, unbeknownst to the candidate 3. Hear negative feedback and just trust it’s true (or at minimum develop a strong bias against the candidate based on hearsay) with no due process for the candidate 4. Reject the candidate / omit them from interview processes to begin with.
I’m sorry but that’s just awful. I have great references who would say positive things about working with me, but I absolutely would never want someone like you to be able to find them like this.