I feel if the webmaster has no problems then its ok. Or else you are going to get penalized by most search engines...
If you are copying content (even if you give credit) without permission, then what you are doing is illegal.
If you are copying content of other site with OR with out permission (thatz not a matter), then you will surely get punishment from G for duplication of content!!!!!! For G Content copying is a BH method.
The pages containing the duplicated content may get a penalty from Google in that Google will not index the duplicated content so it will not appear in searches. Google can apparently do this on specific paragraphs of text.