You’re taking the idea too far and out of context. It’s no different than what you and I already do in real life situations. The idea of a web of trust is how you already gauge everything and everyone. You don’t blindly trust people or give them your attention or access to your life, or at least you shouldn’t. You filter them through your friends, through their professional qualifications, through your prior experience, and so on. It’s just taking that concept and using it to filter who you allow to have your attention online.