I recently had an experience where a source of mine blamed me for something that was not my fault. He then tried to guilt-trip me into doing my job the way it would most benefit him, disregarding how it might effect my professional time. When that didn't work, a colleague of his attempted to bribe me (yes, with money!) to do as he saw fit. I still refused. I was completely disgusted and embarrassed about his behavior. It was condescending, demeaning, selfish, unprofessional and incredibly rude.
I am appalled to realize this type of behavior happens beyond the playground. It is bullying, by every definition.