That's how Google Books, the Internet Archive, and Amazon (their book preview feature) operated before ebooks were common. It's not scalable-in-a-garage but perfectly scalable for a commercial operation.
The books that are destroyed in scanning are a small minority compared to the millions discarded by libraries every year for simply being too old or unpopular.
Book burnings are symbolic (Unless you're in the world of Fareinheit 451). The real power comes from the political threat, not the fact that paper with words on them is now unreadable.