I've got a question getting lots of me-too answers, how can I get it semi-protected so that only established users can add answers?
Consider it done.
The ideal approach would have been to flag the non-answers. Once the third answer by a new user is deleted, a question is automatically protected by the system.
If a question doesn't have more than three deleted answers, it generally shouldn't be protected. We don't want to artificially block users from posting valid solutions.