One of my neighbor's kid is screaming ALL the time. Every day sometimes for hours. I started to wonder if there's child abuse going on or the kid is just simply can't behave. I do not want to accuse anyone and the parents to have a problem if there's nothing going on, however, what if there IS something wrong? I do not want to get involved, but the screaming is quite disturbing.

DEFINITELY report it.  You don't have to give out your personal information either, it can be anonymous...just report what you posted on here and someone will come out and investigate. A child screaming that often (and that loudly for hours on end) is not normal.  Please, please report it - you might be saving a life. 

Each state has a hotline to call...in Florida, the number to call is 800 962 2873 and the website is http://www.dcf.state.fl.us/abuse/