Well plagiarism is against the rules. I am only critical because I was accused of something without actually breaking any known rules so now I'm more skeptical. That said if you find a word for word copy of someone else's work being treated as their own original work then it is plagiarism. The only thing he had to do is put his sources and use quotes like myself and others when citing the work of others.

I also agree that in your post if you would have just tried commenting on his posts that he is doing something wrong you would have given him a chance to explain himself and change his behavior. This action of yours could cost him followers and damage his reputation. It will be hard for him to get upvotes now because why would we trust that all of his future work will not be copied without reference?

The tone on Steemit and the way Steemit is deteriorating as a community is a bigger concern to me. If this were an isolated situation I wouldn't care but it seems many as being accused of some kind of corruption. Steem abuse is too freely thrown around lately in my opinion even if in this particular case you've provided evidence.