The link he posts on Bitcointalk doesn't qualify as a source, as it's not linking directly to the original source. I'd say it's plagiarism.
Clearly,looking at it closely by your statements and observations it's blatant plagiarism..
Plagiarism has to do with copying other people's contents and posing them as yours,and on this forum we are only concerned with the links being posted in here,and since the culprit @sell100 has failed to do so, but posted his own links on this forum(we actually do not care were its linked to),which actually isn't where the contents are from..
Let's put it this way someone could probably drop him a merit without clicking on the link,thinking it's probably the OP's work,that way he could have cheated the system and got away with it