Plagiarism is not a simple mistake in most cases, it's a conscious decision that people make in order to increase their post count and make money off of that.
Frankly, anyone who engages in copying other people's work without giving proper credit for it, should get banned immediately without any exceptions.
This is utter bullshit. I almost made this mistake
today, and the only thing that reminded me to review my post was all this plagiarism paranoia that has been going on the past few days. I
did not even know where the thing that I posted was from, i.e. had absolutely no idea it was plagiarism without a source until I looked it up.
I really don't know how someone could make a mistake like that. I mean the chances of you accidentally writing the same content as someone else, word-for-word, are just so small.