Addressing this specific item, providing a link does, technically, as per the forum’s interpretative jurisprudence of it’s rules, avoid the chances of a post being banned for plagiarism. Nevertheless, link references should really serve the purpose of something along the line of:

-   Allowing readers to know where the core information of the post is derived from.
-   Allowing readers to further read on the topic through the references.

Copying a whole article, or even fragments, and adding a source link at the bottom, could be reported for being a low value post (not always, and mods may or may not agree). Unless it’s a really pressing matter (i.e. very important safety warning), the poster should have time to at least summarize, criticise, question, or write a versed opinion on the information, making the post his own, but including the references for the purposes depicted above within this thread. A simple copy/paste + link is generally a lazy attitude, with a pinch of being deceptive.