As far as forum rules go, providing the source is enough. Even just adding quotes ([quote] or "...") without giving a source would probably be enough to avoid a ban. Contrary to popular belief, the plagiarism rule and application thereof is very lenient. It's usually fine as long as moderators can see that the user didn't intend to pass the text as their own.
Now whether starting a paragraph with "I would like to..." and ending it with copypasta and the source being mentioned only somewhere in the fine print constitutes good writing style - that's a different discussion. I think that's misleading borderline on dishonest. A literal quote should be formatted as such.
In a stricter sense like in case this was published somewhere else, what was done here could be counted as plagiarism even if a credit was given at the end of an article or a book for example?
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I'd be interested to hear from others on this. I don't know if it's a witch hunt or not.
Does it even matter if it is witch hunt or not? airfinex is actually raising a good point if we look at this objectively and think of what plagiarism should be. It's like what suchmoon said, plagiarism is taken lightly by moderator.