I've not thought of it that far however, if you've got an idea, please share.
Discussion
there's no way to know this kind of thing for sure. That's sort of why it works.
how long someone has been in their field is the best proxy, I think. did someone just pop up out of nowhere and is well capitalized? that glows.
the long they've been around, the longer they would have to be "embedded" or whatever, which is less and less realistic the longer it is and the more niche the field.
There's most definitely no sure way. I wouldn't know to be honest. You're right on the glow bit. They're here for sure. Perhaps, lurking if not active agents of chaos and persuasion. But that could really be anyone.