I think there are quite few things in programming that can only be implemented one way. I see it as similar to music in that almost every song have notes going

I think there are quite few things in programming that can only be implemented one way. I see it as similar to music in that almost every song have notes going up or down the scale. Obviously there can't be that many variations, but then the important distinctions is often in the details. Applying copyright on a single function is like applying copyright on a single riff. Sometimes the legal system will accept it, but it should be the exception rather than the norm. Fair use seem to had a change in scope. Historically it seems to be mostly about things like "play a clip in order to comment on it.", but now we have things like google making a copy of all books ever written in order for people to search through them. Similar arguments has been made over copying news articles from news sites in order to put a portion of it in search results. A stack overflow-like search engine that trawled proprietary code bases would likely be sued, but in theory they could argue fair use just like google.