Yes, and they are promptly removed.
Occasionally this is true, but most of the time these people post prolifically for months before an unmistakable pattern of abuse emerges. Free Republic unlike the Democratic Underground on the whole is very tolerant of varying points of view.
I once spent a significant amount of time researching a certain individual. After the person was banned I found that the threads were not nearly as lively or fun. Despite the malevalent intent of the person, the result was that it sharpened up the rest of us who were mostly of like mind. Without that person... we were not challenged nearly as often and the content of the threads suffered. So in truth I appreciate bantering with the opposition. Thank you Kleon for your contributions here. We strongly disagree but that is what makes it fun. ; )