Blocking your posts from readership is the antithesis of viral growth of the platform. You are being paid because you are supposed to be onboarding new users with your content.
It seems to me the only problem such stalkers can cause for your blogs is they can spam the comments. I think a feature which enables to you offer a recommended block list to your readers, is sufficient. Then your readers by default won't see the comments which you've chosen to block. But they can always see these, because demand will be such that clients will offer to display the blocked comments.
Synereo is like using a sledgehammer to kill a fly. You don't want to kill readership as that is the entire point. Medium has 20,000 weekly bloggers serving 25 million monthly readers.