I have been following this question with interest - History of public/private/protected - and noticed that shortly after a new answer was posted by Neil Butterworth, one of the original answers was updated to include this extra information. I have seen minor clarifications based on other posts before, but never such a wholesale import of another answer.
Was this a reasonable thing to do here? Clearly, wanton cannibalism of other answers isn't reasonable on a site where multiple answers with distinct identities are supposed to compete. But there is an argument to seek to improve one's answer, particularly if a concept mentioned by another may be better phrased or explained.
What are the boundaries that define when its acceptable to incorporate information from other answers into your own?
Edit: Marc Gravell points out that in this case, the datestamps prove the edit came before Neil's answer, so this is a terrible example. But the general question stands.