Youtube does this in video description and comments. If I'm scrolled down there to read comments, maybe I want to actually just read them and not click to read them?
Reddit does this. I don't know what reason I have for reading a thread of comments other than reading comments, so why do I have to keep clicking read more?
Twitter evidently does this. If I'm reading a thread, why do I need to click to read more? And after a couple dozen posts, click again. In this case, it also seems to expand the unread posts above the point where you're currently scrolled to, so you have to scroll back up and manually figure out where exactly the last post you read is and where the new stuff begins.
Many shops do this, by cutting product descriptions at a few lines so you can't read what the product is all about without clicking read more.
And they do the same thing with reviews.
I'm really tired of clicking read more over and over again in places where reading is the whole point!