That makes sense, but isn't it something that could be handled by downvotes, muting him on your end, and/or posting about it to your many followers?
I'm not super savvy, but it seems that blacklisting might be overkill or even further inflame the situation. Blacklisting does seem to be able to provoke rancorous reactions, as is showcased here.
Help me understand why the more mundane routes were insufficient.