Who do I call to report defamation and harment on Craigslist Rant /raves section in chicago?

Ok im just a stay at home mom but I go and look at what people post in rants/raves section in the chicago part of craigslist ONCE in a while. Someone keeps posting this guy's whole name, first and last, and his town, and says the guy is a ual predator ONLINE. I'm getting sick and tired of these people accusing and defaming someone. Innocent or guilty, you don't type someone's name on there. Then me mrs. peabody tries to do something about it and all I get from Craigslist is an automatic response after I have copy and pasted two things the people have posted. It says to call your local police. Then I call that guy's police department from his town and I get transferred to the "records" department and I leave a message there with some lady's vmail. Did anyone ever try to good for the world and the world just **** right back in your face? Just so you know I called Craigslist and all I get is this recording and I click "o" for operator and I eventually got hung up on. I think Craigslist needs to be revamped, you can type someones information on there and no one gives a damn. All Im getting are dead ends!!!