Running out of hands
On one, being able to search any book ever written would be wonderful.
On the other, as the author of several, including one on something with a significant anniversary coming up, I am less keen.
Looking at the US 'fair use' rules:
"The purpose and character of the use, including whether such use is of commercial nature or is for nonprofit educational purposes" - are Google showing ads when they show my work? If so, I want a substantial cut of the money, datafucker!
"The amount and substantiality of the portion used in relation to the copyrighted work as a whole" and "The effect of the use upon the potential market for, or value of, the copyrighted work" - as has been said, for novels, having numerous chunks available may not be such a big deal. For those of us who write about real facts rather than making up our own artistic reality, 10% of the whole can represent 90% of the value (as with programs!)
"The nature of the copyrighted work" - sadly, the nature of authors' and publishers' work is that of something that has not had billions spent on lobbying for increases in protection over the past century.
Looking at the examples of activities that courts have regarded as fair use: “quotation of excerpts in a review or criticism for purposes of illustration or comment; quotation of short passages in a scholarly or technical work, for illustration or clarification of the author’s observations; use in a parody of some of the content of the work parodied; summary of an address or article, with brief quotations, in a news report; reproduction by a library of a portion of a work to replace part of a damaged copy; reproduction by a teacher or student of a small part of a work to illustrate a lesson; reproduction of a work in legislative or judicial proceedings or reports; incidental and fortuitous reproduction, in a newsreel or broadcast, of a work located in the scene of an event being reported” - none of that is what Google have done: automatically reproduce verbatim, without permission or payment, as much as their secret algorithms want, to anyone, for any purpose. There is no review or criticism, no scholarly analysis, no summary, etc etc.
But, as I say, being able to search any book ever written would be wonderful. But not if it's controlled by a company seeking a monopoly.