Oh man I volunteered to moderate on a large gaming related forum ages ago. The amount of BS you deal with along with personal attacks and etc is pretty high. I never felt emotionally upset by it as I felt you had to maintain an even keel .... but it certainly is not a job for everyone and the rub is the folks who WANT to do it the most are often the worst at it. Being a good moderator is not a skill everyone has, but it's also not valued in any real way by most communities / companies.
Really the most frustrating aspect were the non trouble users who seemed to go to bat for the folks who were truly bad actors because of some perceived injustice (lie)... and all the meta that goes into that.