If you report a post on fb, can the person who posted it tell who reported it?
Don't worry, your report is anonymous. When something gets reported to Facebook, we'll review it and remove anything that violates our Community Standards. We don't include any information about the person who filed the report when we reach out to the person responsible.
If Facebook allowed others to know who had reported them, it could result in a dangerous or violent stalking type situation and maybe for that reason Facebook keeps this information private.