As long as he/she provides the sources, that will be within the rules. Regardless of that, such content should be placed within a "quote tag" (some try to bend the rules and get away with it).

Can you find him/her (would like to evaluate his/her case [in order to have a clear image of the situation])?

I have come across users that also do this in my post review service but have not awarded any merit for those posts. Some of these users just do this to get merit and rank up to be able to participate in signature campaigns.
I encourage others to no award merit for these individuals.

Yes, I agree, the copy/paste must be placed in a quote tag but of course they shouldn't copy/paste the whole article (everybody can read it in the link provided with it) just some parts of it. Most importantly, they need to provide their own view on it otherwise, it does not bring any value to the discussion.

Good point. Sometimes I'm having dilemma when I want to award users with Merit, especially Newbies and Jr. Members. I see good detailed posts made by these users but I'm not sure that's original content written by these users or it's just copied from somewhere else. I'n too lazy to make research about content of these posts, so usually I avoid to send Merit for these posts.

Detailed posts, which are good but do not attribute sources, would be an ideal candidate for investigating for plagiarism. A quick Google search usually works. Sometimes, users go to great lengths to hide plagiarism - changing characters, using a thesaurus, etc.
If you do a quick and dirty check and do not find plagiarism, you may consider giving merits!

Seems to be slightly differing opinions on this, at least on whether the posts would deserve merit or not. I have seen posts with literally just a link to an article or video, merited simply because they pointed to information that someone was asking for. This I actually agree with, because they have done the legwork and found the answer for the person posing the question. My only real point was that it should be made glaringly obvious that the post was not an original one, not that they don't deserve the merit. I decided not to out the poster in question, mainly because the responses above are mixed on their tactics. If a post brings perceived value to someone reading, and they have stated it is not original with a source link (no matter how subtle that may be), then I guess they are staying within the rules. It is especially true if someone has collated a number of relevant articles into one post, as it will save the reader the effort of trawling the internet in search of their answer. I'll try and check back on the profile (if I can find it) in a week or two and see what I feel then.

Maybe it was just His technique to lure merit sources, some Other users who get merits doesn't always base on what they know, they have gone some research and get some idea to it and then post it as a whole thread with some editing techniques that is why it is interesting, but atleast OP, ask permission to whom it may concern, because accusing someone without any valid reason and proofs and is upon the mandatory rules and regulation then maybe the story will be an ironic reverse.

Yeah, but if there will be some wrong posts merited, I think it will be easy to accuse someone that he is abusing Merit system by sending sMerit to copied posts.

When it's obviously copied article, we must report it. But sometimes user posting only part of article, replacing some words, characters and etc. Then we need to make more depth reasearch before reporting. If I consider to merit post or no, I'm not planning to make research and spend my time.