As webmasters become more concerned about the search engines filtering of duplicate content, I think they will become more concerned about having their content copied. My advice would be to err on the side of caution and ask first if they don't have an explicit policy on the site. Wikipedia, for example, lists on every article their policy regarding reprinting the content (attribution license, they even have a link to generate an appropriate attribution statement).

__________________
The best way to learn anything, is to question everything.
Interestingly Average Security Blog