you are truly right. to detect a fraudulence post is a rigorous work but the truth is that how many posts are people reading per day not to talk of detecting fraud. even when you notice or suspect that a post may contian some fraud how do you go about to know it is really a plagiarized content?
the truth is that an individual cannot detect except if there is someone is seriously monitoring all content being posted to this group which i believe no one will like to do this?
sometimes i try to see the content that people post per hour, you will discovered that what is posted in this community is often more than what one person can read in just four hours not to talk of looking for if it is a plagiarized content.
the treatment you sited above is cool for me and i think it is nice.
Community members screening posts for potential fraud.
They communicate concerns to the community or its most outspoken members
Notify the user of suspected fraud.
Validate suspected fraud or get consensus on it.
Don't vote on the user's article.
but in addition it will be good if some accounts can be deactivated for some days after detecting plagiarizm in a content with the original source being stated in the comment section so that the person will know that people in the community has gone extra mile to detect the work the person is copying from.