There's no identifiable information the mods see (unless the report came from another mod or an admin), but the site admins do know who sent in reports in case of suspected report abuse. People can be really annoying with reports, one guy on /r/askscience got so mad his post got removed that he reported every other post and comment for the past week. Again idk it's the same guy that did that but when you get an angry screeds in the mod messages and every post and comment has a report you can guess what happened.