Users with 3,500 rep (or 15,000
if when we get a site-design) can protect challenges. This makes it so that users who have not earned 10 rep on the site can not answer.
As a user with this privilege, I have no idea when it would be appropriate to use. This is because the idea of "protecting questions" makes perfect sense for a Q&A site with a popular question attracting non-answers or low-quality answers. But we're not a Q&A site! Nobody posts challenges here because they need help with a problem, only because they enjoy coming up with programming tasks and challenging other users to solve them. So pretty much all of the guidelines for when to protect don't make sense on our site. For example, the original announcement says:
So, in the future, if you see a question that is attracting a lot of drive-by noise answers, please flag it for moderator attention. We'll turn on protection.
But that never (or at least very rarely) happens here. I can find lots of old challenges that are protected, (1, 2, 3, 4, 5, etc.). But "drive-by noise" is not the problem. The "auto-protection" is being triggered by self-deletions.
So my question is pretty much when does it make sense to protect questions and prevent new-users from participating on these challenges, specifically in the context of our site? Should we un-protect challenges that were automatically protected by community? Does it ever make sense to protect a challenge that is not attracting low-quality "drive-by noise"?