I found two answers that consist of a single copy-paste of another site with the source given at the end. The text itself is not marked as a quote, nor there is any indication that the whole answer is just a word-for-word reproduction of someone else’s work (well, you may get suspicious as you read along).
One of the answers reproduces an article about the capitalization of internet by Cláudio Moreno in Sua Língua. I have edited it make it clear it is a quote. You can see the original and current version in the revision history. The answer only leaves out the final greeting: «Abraço. Prof. Moreno.» But I wonder whether we should just include it too when we reproduce someone else’s entire article.
The other answer is this one about commas. I’ve edited the other one, but thought it would be best to discuss the matter before doing anything about this one. This is also trickier, because we can say at the beginning the following is a reproduction of another website, but there’s no way, I think, to actually mark the text as a quote.
What should we do in these cases? I think just indicating the source at the end is not enough. That’s what you could do if you used the source for information, but wrote up your answer in your own words.