I understand there are privacy concerns with this, but there is definitely a case to be made for the ability to search for text within images. The Library of Corom around 6 mins into this presentation inspired the idea.
I have long wanted the ability to find text in images in email attachments, PDFs, Bing, Windows Search, etc. Even better, the ability to copy text out of an image inline. A common use case would be getting an email from a coworker with a screenshot of an error message with a long GUID I'd like to search on.