Good article on fair use

Some highlights

[i]Rule 3: Giving the Author Credit Does Not Always Let You Off the Hook
Some people mistakenly believe that they can use any material as long as they properly give the author credit. Not true. Giving credit and fair use are completely separate concepts. Either you have the right to use another author's material under the fair use rule, or you do not. The fact that you attribute the material to the other author does not change that.

Rule 4: The More You Take, the Less Fair Your Use Is Likely to Be

Contrary to what many people believe, there is no absolute word limit on fair use. For example, copying 200 words from a work of 300 words wouldn't be fair use. However, copying 2,000 words from a work of 500,000 words might be fair. It all depends on the circumstances.[/i]

I'm reminded of https://social.ringplus.net/discussion/6903/fair-use-defense-to-infringement

This is good to know. That said, absent express permission/license from the copyright holder, to cut and paste an entire article (credited or not) violates the terms of use specified by the site from whence it came.