The best trust protection is manual "vetting". 

Let Sally endorse Bob as an authentic human. But only once Sally has first been endorsed trustworthy herself. Creating an opt-in circle of trust. 

If a bot slips through the cracks, Sally can remove her endorsement of Bob. Which removes ALL endorsements that Bob made too, all the way down the line. Blasting bot-nets out of the sky.

Only endorse people you trust, and people you trust to make trustworthy endorsements as well. 

 Yes, WoT makes this easier and is what I use for the 140.f7z.io relay