Several times have I rung my bell at people walking out into traffic or the bike lane (staring at down their phone) and been yelled at for it. People crossing Pennsylvania at 18th are big offenders of this. I may or may not buzz them when I have the light and they don’t.
Actually, just this am at the top of the S Curve of Death I rang my bell and called out to a jogger (with no lights!) that I was approaching; without looking over his shoulder, he turned left to exit the path onto the side street there. He almost smacked into me but this was, according to him, entirely my fault.