Just now, the following two questions have been protected:
- What is the difference between cheap and less cheap road bikes?
- How do I measure the size of my bicycle frame?
The immediate context is that the first question received a very poor answer by a new user and the second got a link-only answer from the same user.
I don't think that is nearly enough unwelcome activity to merit protection. We are perfectly able to deal with one bad answer to a question by the normal means of downvoting, flagging and deleting that answer. This has pretty much no down-side, whereas protecting the question means that a potential new user who might be able to give a good answer to either of those two questions will be prohibited from helping us become a better site.
I don't have enough reputation to see deleted answers, so it's possible that several bad answers had been posted and I arrived on the scene just before clean-up was completed. It's also possible that these questions have a history of receiving bad answers from new users and these two answers were the straws that broke the camels' backs. If either of those things happened, then protection may well be justified. But I don't think it's appropriate to protect because of just one or two bad answers.