The capture of document images for use in DL's is often carried out in large-scale batch operations. The operations are almost always designed narrowly to meet the immediate purpose. For reasons of cost, only rarely will the documents ever be rescanned. In fact, documents can be damaged or destroyed in the process, sometimes deliberately, e.g. spines of books cut off to allow sheet-fed scanning. Even more drastically, many libraries have discarded large collections of books and documents after they have been scanned, triggering anguished charges of violations of the public trust.