This PSE question is now closed for being a duplicate. This means that no one (less than 10k rep?/no unprotect priv.) can answer. The purpose of "protect question" is to "Protect this question if it is highly active and likely to receive spam activity or non-answers. Anonymous and low reputation users can’t answer protected questions."
However, the "protect question" dialogue/button is available even though the question is closed - I just clicked (then unclicked) this button and the question went into protect mode. So my question is, is there anything more this action does apart from preventing anon/low reputation users from answering? Or could it just be something the developers haven't got around to fixing if it needs to be?