Earlier today a user posted three answers to three different questions, the final two of which were almost entirely copy-pasted from the user's original answer, and each with a link to a YouTube video posted by the same user. This appears to be the first answer, followed by this one, and finally this one. None of the answers mentions or provides links to any of the other copies.
Is it acceptable to copy your own answers like this on Stack Exchange sites? I have to say that it doesn't seem right to me, but I don't know what the policy is on such answers here. In the publishing world, self-plagarism is frowned upon, but I don't think that Stack Exchange adheres to this standard. Still, it seems like the least that such an answer could do is to cite the original answer and provide a link.