It happens so often, I don’t see it as being accidental.
Here is the reason. A blog type website generally cut-n-pastes information from other sites. The linked to site has text in another format and that gets repeated as the same text in their own blog article. There is often a photo or graphic that repeats the text as a caption.
If the complete content gets posted here with one cut-n-paste from the blog site that text is copied three times for us to stumble through. The Freeper should proofread and delete the duplicate text but that is usually an after thought. It's not intentional but just part of the internet architecture.
Makes sense, thanks.