I find a simple two-step process works best for me.
First, I get consent.
To do that, I might say:
“I have negative or unflattering information about ____ that I’m willing to share with you. Would you like to hear it?”
If they say, “No,” I respond with something like:
“That’s fair. If you change your mind, you may reach out any time.”
AND I LET IT BE.
If they consent:
I give as full an account as I can, stating honestly what I KNOW (first hand or witnessed) and what I have heard. When possible, I also give contact information to others who may have knowledge (first hand or witnessed information), if I have their consent to do so.
I never suggest to anyone that my information is more important than their personal judgement or right to refuse. It is simply information that they may or may not want to use to form their own opinion.
No drama. No padding of facts. No telling people things I’m not sure of. No forcing people to listen to things they don’t want to know. No trying to force someone to take actions that are none of my business.
What ways have you found works best for you in spreading the word about a predator or unsafe player?