It is important to give credit where credit is due. Every time you publish something without proper accreditation, you are taking a risk. You may think that it won’t matter because the audience is small, it is obscure, or it is isn’t important. You would be wrong on all counts.
What could happen if you are caught trying to pass off something as your own? Maybe nothing the first time, but if you post a written piece of work on Facebook, Twitter, or your own blog, it will get passed along. Every time a fresh audience views what you have written, the chances increase that you will be caught out. Why take the risk?
Depending on what you try to pass off as your own, you could get a failing mark on a paper, you could be publicly shamed, or you could be sued. There is an easy solution. Ask for permission. This is a case where it is not better to ask forgiveness than ask permission. If you want to publish a complete article, or even substantial portions, write to the author. Explain where you want to publish it, explain why you want to, and wait for an answer. Many writers or researchers are happy to have their works exposed to a wider audience. If you are providing a quote or a small excerpt, often acknowledging the author is enough.
People familiar with your writing style will be quick to notice if you suddenly “write” something that sounds radically different from your usual style. Once one piece of work is questioned, every piece written before or since will be subject to scrutiny, whether it is yours or not.
Give the credit where credit is due. After all, you don’t want to crank up your computer and find that someone has done the exact same thing to you. Definitely not playing fair.