I appreciate this, Jeff. I've seen it many times as well. For example, Thomas Pong loves to steal people's stuff. One reader made me aware of this recently.
But there's not much we can do. It's an internet problem. These content thieves often change a few things so they can get away with it.
I agree with taking this seriously. Would be great if Medium would introduce a point system or something. Three strikes and you're out!