Here is a reply from someone who has been in the trust system for a very long time and currently a DT member. You can visit my thread on the reputation board for more clarification
No offends guys but I haven't be clarified my questions haven't been answered. If you say an account used for collateral should be tagged for account farming when should the red tag be given? After lone default (to prevent account selling) or immediately it's offered as collateral and should all accounts involved be tagged for account farming?
Both the lender and the user should be immediately tagged.