I do not understand this badge.
It says: zero accepted answers: for whom ? for me? I found one user having this badge without posting any question. How could be? This is the user's link.
Can you clarify it please?
The original poster is the person who marks answers as accepted.
If you look at the answers that user has posted they have a bunch of accepted answers with a score of zero, thus earning the badge.
I think the idea is to reward people who are quietly answering questions and not getting recognition from people other than the person asking the question.