When I was completing my MBA I took an online course through SBU and an online elective course at another institution.
The 7 week online course at the other institution had a requirement to complete discussion boards based on the assigned readings. The assignment asked us to post our original thoughts and then comment on posts by our classmates. During week 3, I noticed another student was plagiarizing my discussion posts by changing one word per sentence. I was stunned a graduate student would to copy my work/plagiarize in a business ethics class! Fortunately, the teacher noticed and could see my posts appeared before the other student uploaded my work with tiny changes. The solution was the teacher changed the format of the posts on Moodle so we could not see what other students wrote until we posted our own original work.
I learned from that experience and it changed the way I use Moodle discussion forums. When I teach online and have discussion boards, I allow the students to see the posts of others for the first assignment to get a feel of the assignment and discussion board expectations (and I give all students a lot of feedback so they understand the assignment expectations). Then, I change the format (in the discussion post settings) to the "Q and A forum" format which requires students to upload their own post before the work of others is revealed. Although there are ways around it, I think this format encourages students to do the course work and post original content, and not just reword previous posts. Depending on what the learning objective is for the assignment, it may be wise to force students to post before seeing the work of others. I also imagine there are assignments where it is wise for students to be able to see what others have written before they upload their work. I am now grateful I had the experience in the ethics course as a student to see the flexibility faculty have in making adjustments mid-semester, and learn about the variety of discussion forum settings Moodle has available to facilitate online learning engagement.