Search Terms and Unknown Query
You may notice that when viewing the Sources widget most of the searches say [unknown query]. This is a problem that affects all analytics services, including Google Analytics themselves.
In 2013 Google changed the way they report keyword searches so that they are all encrypted. This means it is impossible to recover the original search term used. They did this to prevent very aggressive marketing companies from gaming the system. Historically businesses would try to manipulate all search terms so that their website would always be at the top of the list no matter what terms you had actually tried to search for.
This created a negative experience for all Google users as you could never actually find what you were looking for. Understandably Google decided to stamp out the practice completely by encrypting search terms. Most other major search engines decided to do the same shortly after.