While going through the review queue I was shown the first answer of a new user, correct, well explained and perfectly formatted. I thought this was strange, so I opened the original question page and found the identical answer posted by an experienced user. I upvoted this answer and flagged the answer in the review with the comment "identical copy of existing answer".
Then I was told that this was a test and I didn't pass! Didn't pass because I take the reviewing seriously and identified a case of plagiatism? If you do such tests, then don't link to the real question, but also to a fake question site where this answer is shown as posted by a new user. I would gladly have upvoted it then.