I think this is a really bad solution that only reinforces bad practices of hiding content. Even worse than direct censorship, it generates more problems than it solves.
When everyone knows it, I agree. As long as it is not mentioned anywhere, and people do not write hundreds of comments, its just a failed captcha that appears more often when someone writes something in range, possibly forcing them to rethink their argument. Its no solution for all, more an interesting thought.
