I think Mpamaegbu likely intentionally plagiarized his post. The post in question is several years old, and I am not sure if he was participating in a signature campaign at the time. IMO he is sufficiently established of a forum member that a temp ban, rather than a permaban would probably be in order.
If his intention was to plagiarize, he wouldn't indicate that he took content from someplace else by writing "smuggled out snippet below" right there in the first sentence of that incriminating post.
Okay, that is not something I had substantially noticed before. I have negative opinions regarding copying content (even when citing said content), as I discuss below, however, I don't think this substantiates any kind of long-term ban, nor long-term signature ban.
There are a lot of people who basically copy entire articles in a thread and have a citation at the bottom of the post. This is not plagiarism, but IMO is another problem as the post has virtually no original content nor commentary. The above is often not even someone summarizing an article, it is copying entire articles.
If not formatted properly that's plagiarism too (not on bitcointalk though) and low value shitpost that should be reported & deleted.
My opinion is that this kind of content is low value in nature. I wish people would not do this. However, as long as forum rules (and practice) allow this, I cannot in good faith favor a ban for doing this.