I do not think people change, I just think they hide wo they really are very well over the Internet. I have seen a couple of cases where a user farms trust for months or even years before making away with a significant loan amount. This indicates that to have been their initial motive for creating an account on the forum.

This from all indication does not look like that. But it matter much what it looks like or how I perceive it, another lender suffers yet another loss frustrating such well meaning users and demotivating others who want to join in.
Going strictly with collateral based loans seems like a good direction to take in the face of all the possible indication of losses.