The simple answer is that this is very rare in small claims cases. Because the law values a plaintiff’s ability to vindicate his or her rights in court, it would have to be very obvious that the suit is outrageously frivolous or harassing. Therefore, it is very difficult for a defendant to be able to counter-sue on these grounds. In fact, many small claims courts don’t even recognize “frivolous” or “harassing” as appropriate bases for a counterclaim in small claims court.