That is plagiarism, you can't use a whole of text even if you indicate the source, he or she does not even own a one sentence in the post, that's purely plagiarism.
''copying so many words or ideas from a source that it makes up the majority of your work, whether you give credit or not (see our section on "fair use" rules)'' plagiarism.org
Yes, in a scientific world, it is considered as a plagiarism even if we did add the fully reference of the source. To make it as "not plagiarism" thing, one must make the work based on his own word even though he refer to other articles or news, and then you still must add the source.
I believe even in the internet world, it is still a plagiarism, and should lead to a punishment.