Here are some tag wiki edits that directly plagiarize without attribution of any kind (which can be easily found with Google). However, they were accepted, because many reviewers did not realize that they were plagiarism.
discussion- How could we find plagiarism in tag wikis more effectively? Right now, as seen in these examples, almost nobody even looks for it at all. This is a very big problem.
feature-request- I suggest that we automatically run all the new tag wiki/excerpt suggestions through a plagiarism detector. It doesn't have to be hard; the way I found them was by copy/pasting the text into Google.
Also, single users can massively plagiarize. This is getting even worse; I and another user used up all of our reject votes trying to stop a single plagiarizing user. The edits are still getting accepted, as you can see in all of these links! (I have left a comment here (apparently which is now deleted) and flagged, but almost everybody else will just approve the edits and move on.)