Here's another angle to consider too. I've spend much of the day crafting a very professional and concise "I cannot by the ethical standards expected of me by my profession accept you as a client, but I can can direct you to other professionals who may be able to. Please do not come to my place of business without an appointment, as it is posted on our door all sessions are by appointment only and it's inappropriate to loiter otherwise. I am not interested in further contact with you." Sort of statement.
However, yes, in addition to maybe not giving this guy a chance to explain his side of the story, it is also a fact that declining a client strongly (or firing someone) is often a trigger for violence. This guy is unlikely to catch me at work unless he's physically stalking me. But there are two other people in my suite that have more regular hours and are around more. It's not only me that's endangered if that happens.
So I have to be a careful wordsmith, warn my suite mates to keep an eye out. It's possible they may not renew my lease in a month or so and I can't blame them--they have to make safety considerations too, we are all solo practioners in an office park that's somewhat private.
Does this satisfy you that I'm still keeping the feelings/considerations of this poor man on the table, @Derp? Adulting enough for you? Or did you not realize the very real and pragmatic if not "fair" to me a stalking incident like this has towards not only my person but also my livelihood because workplace violence is a thing, it has nothing to do with who's got a penis or not, and it is a reality that all business owners have to take into consideration?
I would say the odds are that the guy will leave me alone. But I can't be sure, and as @arkandel explained better than I, it is his crossing so many boundaries to get this point that means I cannot assume nor is it ethical for me to assume that this is something that's just harmless--because there's not just me involved.