I belong to a list serve that has posts several times a day from various group members. One of the members posted one day complaining about various work conditions. Remembering that digital postings have a way of living on forever, this was probably not the best forum for that complaint. The negative posting could very easily have gotten back to the district administration in some way and posed a problem for that person. As I tell my students, don't post anything you wouldn't want your mother to read.