This kind of thing has been going on for a while:

 - http://meta.stackexchange.com/questions/60957/copyright-and-questionhub-harvesting-questions-from-so

 - http://meta.stackexchange.com/questions/24611/is-it-legal-to-copy-stack-overflow-questions-and-answers/48962#48962

In that case I *think* question-hub is doing it right, but check for attribution to be certain.