I have spoted two in the past, highlighted what they were doing and they stopped and vanished. Not here on nostr. In a forum and a site with a lot of comments. Sometimes, just sometimes, they can be distinguished because they have unique goals and sometimes that doesn't fit so well. And of course they are sneaky etc as you said. So next time that you will read something that doesn't really make common sense and has a sneaky vibe, ask yourself if you are reading a mosad comment.