This question (which apparently just picked up a new mediocre answer, thus moving to the top of the questions stack) was apparently auto-protected by Community some time back. My question is why: was it attracting a high level of spam or the like? Are there deleted answers I'm not seeing that caused some sort of automatic threshold to trigger? On the face of it it looks like a slightly awkward question with an excellent answer, and it's hard to see any reason why it would have been protected...
You're not seeing it, but there are five answers that have been deleted.
I don't know if the protection was automatic or not, but that's likely the reason. The protection was automatic after three new users had their "answers" deleted from the page.
It's a very popular question among new developers and new users to the site. Questions like that will often have people asking for help through the answers (since they can't comment yet and answering is an easy way to abuse that).
Users with 10k or more rep can see deleted questions and answers.