Seems like a bait-and-switch. Do free labor for a good cause (PD books), turns out you're just growing Goolge's library which can be taken down at a whim.
No, that was the Distributed Proofreaders project, which is unrelated (just used as an early example of crowdsourced OCR).
reCaptcha originally helped digitized the archive of the New York Times, but that was finished years ago.