Optical character recognition, also known as OCR, is really an amazing technology. If you aren't familiar, it takes images and reads the text on them. For PDFs, it can make the words it finds searchable, selectable, and whatever else you may want to do with them. The better implementations of OCR work well enough that they pretty much make CAPTCHAs pointless. And while Google Drive has offered this function in English for over a year now, it is now rolling it out to over 200 different languages.