"I wonder if this would not be the way for newspapers to prevent Google News from scraping "
It is as simple as writing two lines of text to a robots.txt file in the root of your website - it'll literally takes 1 minute to do.
Yes, yes I know what you're thinking "if it is that easy why is there such massive fuss and legislation being passed in various countries to stop Google's vicious news site from accessing all their lovely content?"
Why indeed? I'll leave it as an exercise for the reader to ponder that one!
PS: if any new article website wants to pay me just 50% of their lawyers rate for trying to stop Google News I will do this change for them and stop the nasty Google News in it's tracks without risking a court appearance.