We teach students that plagiarism is a serious ethical violation in science. But, as a reviewer I've seen a surprising number of articles in which the authors either don't (1) directly quote and give credit for "lifted" text from another author or (2) paraphrase the work of another without credit. This doesn't even include the number of times an author mentions a "new idea" that has quite a history that remains uncited or referenced, and so forth. I'm curious about how common this is in specific sciences and social sciences today? When I've detected it as a reviewer perhaps the article is rejected but it doesn't seem like more than that happens. So the other part of my question is what happens when the plagiarism is pointed out?