Any rank can be guilty of plagiarism, but it's extremely frustrating for me to find out that a noob who I was about to give merits to plagiarized the post--and that's because I badly want to merit newbies who write good content like Mister99 did. 

If bitcointalk attracted new members who could write intelligent, well-thought out, and interesting posts, it would be like a beacon of hope.  That's not happening however, and in fact the exact opposite thing is happening.  The forum is attracting people willing to do only the bare minimum to satisfy bounty requirements, and some of them can't even do that; hence, they copy/paste material from the internet.

My suspicion, too, is that when a Hero or Legendary account gets busted for plagiarism, the account has probably been hacked or sold.