The feature I'm talking about is direct vs indirect trust in WOT. If an indirect trustee is deemed untrustworthy, it may say something about the chain of direct trust links leading to him. If someone I introduce into the trustee network turns out malicious, I might get somehow penalized, as well as others I introduced. I realise WOT is designed with authentication in mind, but maybe it could serve more general trust systems. Not sure.
https://en.wikipedia.org/wiki/Web_of_trust
I've not examined it closely, but Web of Trust follows that train of thought at least to an extent.