If I want to copy content without authors permission, I won't copy and paste and will just wget the shit out of your web page and carry on. You prevented nothing.

But as a regular user, you just made me angry preventing me to copy and paste or adding obnoxious content (which I'm going to delete anyways).

So you traded a light barrier (if any) to unfair users for a huge annoyance to legitimate ones. Not very smart IMHO.