I have a customer that asked me if is possible to limit authorization to a single library for some users. He wants them to just read the files in the library but to forbid downloading them. I couldn't find any option for that.
Out of the box, this isn’t possible. You can, however, restrict both download and printing with Information Rights Management for all users, but not for a group of users. And since there is a snipping tool and a print screen function on all operating systems, users can with a little effort still get the content of document and save it somewhere else. So this doesn’t make your document content protected, just less vulnerable.