I think for the most part the majority of posters debate in a mature matter. once in a while a topic might hit very close to home and some passionate views or some comments that are probably not within the normal character of the poster shows up. I have no problem with this, and I personally have experienced this. I think we all have.
I do have a problem with a poster who´s insults and demeaning remarks are a character trait. It happens in all their posts. The funny thing is, in a debate when a person gets emotionally charged and starts spewing insults and the like they lose sooooooooooooo much credibility. They might have had valid points to begin with but in the end the way they express themselves takes center stage as opposed to the information they give.