Does Google's Knowledge Graph scare you? It isn't a new topic, we talked about it before when asking if we should markup our pages and during Amit Singhal's swiss army knife. If searchers can get the content and the answer directly in the search results, why would they click to you?
Amit said that Google just gives a quick snapshot of the answer but the details will be on the publisher's site and thus the searcher should click deeper. That being said, Google wants to answer more and more detailed questions right on their search results page or via Google Voice/Now/Glass/Android.
A WebmasterWorld thread thinks some webmasters are overreacting and there is not that much to be concerned over. His example, search for [doughnuts] and Google doesn't tell you how to make doughnuts, but it does give you nutritional facts on them. So if you run a recipe site, you are okay for now but if you run a nutritional facts site, you are in trouble.
One person responded to that saying, Google rolls "things out in the least controversial way they can...and then turn the knobs later." Maybe.
Here is another example that hits more to home for me. A search for [what is seo] brings up an answer from Wikipedia:
Right below that listing is an article from Search Engine Land missing out on that traffic. Google did have the answer from Search Engine Land months before that but it was replaced by Wikipedia and now, that traffic either sticks on the Google results page or Wikipedia gets it.
If you are the source Google picks, it isn't all that bad, assuming the user clicks through.
But when you are not but you are the number one organic result, it can feel like a zinger.
Do you fear Google's Knowledge Graph?
Forum discussion at WebmasterWorld.